.feature-card,
.use-case,
.tip-card {
    padding: 2.5rem;
    background: var(--card-background);
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
    overflow: hidden;
}

.feature-card:hover,
.use-case:hover,
.tip-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

/* Use Cases Layout */
.use-case-container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

.use-case-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}

.use-case-row:last-child {
    margin-bottom: 0;
}

.use-case {
    background: var(--card-bg);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    position: relative;
}

.use-case:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
}

.use-case-header {
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.use-case-icon {
    font-size: 2rem;
    color: var(--primary-color);
}

.use-case-content {
    padding: 1.5rem;
    flex: 1;
}

.use-case-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.use-case-description {
    color: var(--text-color);
    margin-bottom: 1rem;
    line-height: 1.6;
}

.use-case ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.use-case li {
    margin: 0.5rem 0;
    color: var(--text-secondary);
}

.use-case strong {
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .use-case-row {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .use-case-image {
        height: 180px;
    }
}

/* Fullscreen Mode */
:fullscreen {
    background: var(--background-color);
}

/* Mobile Fullscreen Mode */
@media (max-width: 768px) {
    :fullscreen {
        background: var(--background-color);
    }

    :fullscreen #app {
        width: 100vh;
        height: 100vw;
        transform-origin: top left;
        transform: rotate(90deg) translateY(-100%);
        position: absolute;
        top: 0;
        left: 0;
        display: flex;
        justify-content: center;
        align-items: center;
        overflow: hidden;
    }

    :fullscreen #countdown-container {
        width: 100%;
        height: 100%;
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        padding: 2rem;
    }

    :fullscreen #countdown-display {
        display: flex;
        gap: 3rem;
        margin-bottom: 3rem;
    }

    :fullscreen .time-section {
        min-width: 120px;
        text-align: center;
    }

    :fullscreen .time-section span {
        font-size: min(18vh, 8rem);
        line-height: 1;
    }

    :fullscreen .time-section .label {
        font-size: 1.2rem;
        margin-top: 0.8rem;
    }

    :fullscreen .controls {
        flex-direction: row;
        justify-content: center;
        align-items: flex-start;
        gap: 3rem;
        width: 100%;
    }

    :fullscreen .presets {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 1rem;
        max-width: 35vh;
    }

    :fullscreen .main-controls {
        display: flex;
        flex-direction: column;
        gap: 1rem;
        max-width: 25vh;
    }

    :fullscreen .preset-btn {
        height: 8vh;
        padding: 0.5rem;
    }

    :fullscreen .control-btn {
        padding: 1rem;
        height: 7vh;
        min-height: auto;
    }
}

/* Landscape Mode (for non-fullscreen) */
@media (orientation: landscape) and (max-height: 500px) {
    #countdown-container {
        padding: 1rem;
    }

    #countdown-display {
        gap: 1.5rem;
    }

    .time-section span {
        font-size: min(12vh, 5rem);
    }

    .controls {
        flex-direction: row;
        gap: 2rem;
    }
}

/* Theme: Dark (Default) */
:root, .theme-dark {
    --primary-color: #bb86fc;
    --background-color: #121212;
    --text-color: #ffffff;
    --secondary-color: #ffffff;
    --accent-color: #03dac6;
    --shadow-color: rgba(255, 255, 255, 0.1);
    --success-color: #03dac6;
    --warning-color: #ffab00;
    --error-color: #cf6679;
    --preset-color: rgba(255, 255, 255, 0.05);
    --preset-hover-color: rgba(255, 255, 255, 0.08);
    --preset-active-color: rgba(255, 255, 255, 0.12);
    --preset-text-color: #ffffff;
    --hover-color: #333;
    --border-color: #444;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Light */
.theme-light {
    --primary-color: #1976d2;
    --background-color: #f5f5f5;
    --text-color: #212121;
    --secondary-color: #424242;
    --accent-color: #00c853;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --success-color: #00c853;
    --warning-color: #ffd600;
    --error-color: #d50000;
    --preset-color: #ffffff;
    --preset-hover-color: #e0e0e0;
    --preset-active-color: #bdbdbd;
    --preset-text-color: #212121;
    --hover-color: #f7f7f7;
    --border-color: #ddd;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Purple */
.theme-purple {
    --primary-color: #9c27b0;
    --background-color: #f3e5f5;
    --text-color: #4a148c;
    --secondary-color: #6a1b9a;
    --accent-color: #aa00ff;
    --shadow-color: rgba(156, 39, 176, 0.2);
    --success-color: #8e24aa;
    --warning-color: #ab47bc;
    --error-color: #d500f9;
    --preset-color: #e1bee7;
    --preset-hover-color: #ce93d8;
    --preset-active-color: #ba68c8;
    --preset-text-color: #4a148c;
    --hover-color: #e5d1f2;
    --border-color: #c5c3c5;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Ocean */
.theme-ocean {
    --primary-color: #0288d1;
    --background-color: #e1f5fe;
    --text-color: #01579b;
    --secondary-color: #0277bd;
    --accent-color: #00b8d4;
    --shadow-color: rgba(2, 136, 209, 0.2);
    --success-color: #00acc1;
    --warning-color: #26a69a;
    --error-color: #64ffda;
    --preset-color: #b3e5fc;
    --preset-hover-color: #81d4fa;
    --preset-active-color: #4db6ac;
    --preset-text-color: #01579b;
    --hover-color: #add8e6;
    --border-color: #87ceeb;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Forest */
.theme-forest {
    --primary-color: #2e7d32;
    --background-color: #e8f5e9;
    --text-color: #1b5e20;
    --secondary-color: #388e3c;
    --accent-color: #00c853;
    --shadow-color: rgba(46, 125, 50, 0.2);
    --success-color: #43a047;
    --warning-color: #66bb6a;
    --error-color: #00e676;
    --preset-color: #c8e6c9;
    --preset-hover-color: #a5d6a7;
    --preset-active-color: #81c784;
    --preset-text-color: #1b5e20;
    --hover-color: #dcedc8;
    --border-color: #8bc34a;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Sunset */
.theme-sunset {
    --primary-color: #f57c00;
    --background-color: #fff3e0;
    --text-color: #e65100;
    --secondary-color: #ef6c00;
    --accent-color: #ff9100;
    --shadow-color: rgba(245, 124, 0, 0.2);
    --success-color: #fb8c00;
    --warning-color: #ffa726;
    --error-color: #ffb74d;
    --preset-color: #ffe0b2;
    --preset-hover-color: #ffcc80;
    --preset-active-color: #ffb74d;
    --preset-text-color: #e65100;
    --hover-color: #ffd7be;
    --border-color: #ff9800;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Rose */
.theme-rose {
    --primary-color: #e91e63;
    --background-color: #fce4ec;
    --text-color: #880e4f;
    --secondary-color: #c2185b;
    --accent-color: #ff4081;
    --shadow-color: rgba(233, 30, 99, 0.2);
    --success-color: #d81b60;
    --warning-color: #ec407a;
    --error-color: #ff80ab;
    --preset-color: #f8bbd0;
    --preset-hover-color: #f48fb1;
    --preset-active-color: #f06292;
    --preset-text-color: #880e4f;
    --hover-color: #f2c1d2;
    --border-color: #e91e63;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Mint */
.theme-mint {
    --primary-color: #26a69a;
    --background-color: #e0f2f1;
    --text-color: #004d40;
    --secondary-color: #00897b;
    --accent-color: #1de9b6;
    --shadow-color: rgba(38, 166, 154, 0.2);
    --success-color: #00bfa5;
    --warning-color: #26a69a;
    --error-color: #64ffda;
    --preset-color: #b2dfdb;
    --preset-hover-color: #80cbc4;
    --preset-active-color: #4db6ac;
    --preset-text-color: #004d40;
    --hover-color: #add8e6;
    --border-color: #4db6ac;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Coffee */
.theme-coffee {
    --primary-color: #795548;
    --background-color: #efebe9;
    --text-color: #3e2723;
    --secondary-color: #5d4037;
    --accent-color: #a1887f;
    --shadow-color: rgba(121, 85, 72, 0.2);
    --success-color: #6d4c41;
    --warning-color: #8d6e63;
    --error-color: #a1887f;
    --preset-color: #d7ccc8;
    --preset-hover-color: #bcaaa4;
    --preset-active-color: #a1887f;
    --preset-text-color: #3e2723;
    --hover-color: #f5f5dc;
    --border-color: #795548;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Theme: Galaxy */
.theme-galaxy {
    --primary-color: #5c6bc0;
    --background-color: #1a237e;
    --text-color: #e8eaf6;
    --secondary-color: #ffffff;
    --accent-color: #7c4dff;
    --shadow-color: rgba(92, 107, 192, 0.3);
    --success-color: #536dfe;
    --warning-color: #3d5afe;
    --error-color: #304ffe;
    --preset-color: rgba(255, 255, 255, 0.1);
    --preset-hover-color: rgba(255, 255, 255, 0.15);
    --preset-active-color: rgba(255, 255, 255, 0.2);
    --preset-text-color: #e8eaf6;
    --hover-color: #3f51b5;
    --border-color: #1a237e;
    --progress-bar-background: rgba(128, 128, 128, 0.1);
    --progress-bar-color: var(--accent-color);
}

/* Base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

#app {
    min-height: 100vh; /* 改回100vh以确保全屏 */
    display: flex;
    flex-direction: column;
    justify-content: center; /* 垂直居中 */
    align-items: center;
    position: relative;
    background-color: var(--background-color);
}

#countdown-container {
    text-align: center;
    padding: 2rem;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

#countdown-display {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 3rem;
}

.time-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
}

.time-section span {
    font-size: 12rem;
    font-weight: 600;
    line-height: 1;
    transition: all 0.3s ease;
    text-shadow: 0 4px 8px var(--shadow-color);
    display: inline-block;
    min-width: 2ch;
    text-align: center;
}

.time-section .label {
    font-size: 2rem;
    color: var(--secondary-color);
    margin-top: 1rem;
}

/* 主题切换过渡效果 */
body {
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* 数字切换动画 */
.time-section span {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: inline-block;
}

/* 全屏切换动画 */
#countdown-display {
    transition: font-size 0.3s ease, transform 0.3s ease;
}

/* 最后10秒动画效果 */
.time-section.ending span {
    animation: pulse 1s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
        color: var(--accent-color);
    }
    100% {
        transform: scale(1);
    }
}

/* 主题切换按钮悬停效果 */
.theme-option {
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.theme-option:hover {
    transform: translateX(5px);
    background-color: var(--hover-color);
}

/* 控制按钮悬停效果 */
.control-btn {
    transition: all 0.2s ease;
    position: relative;
    overflow: hidden;
}

.control-btn::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.3s ease, height 0.3s ease;
}

.control-btn:hover::after {
    width: 200%;
    height: 200%;
}

/* 预设按钮动画 */
.preset-btn {
    transition: all 0.2s ease;
}

.preset-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow-color);
}

.preset-btn:active {
    transform: translateY(0);
}

/* Theme Dropdown */
.theme-dropdown,
.settings-dropdown {
    position: relative;
    display: inline-block;
}

.theme-menu,
.settings-menu {
    display: none;
    position: absolute;
    bottom: calc(100% + 16px);
    right: 0;
    background: var(--background-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 16px;
    min-width: 240px;
    max-width: 90%;
    max-height: 70vh;
    overflow-y: auto;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.2s;
}

.theme-dropdown.open .theme-menu,
.settings-dropdown.open .settings-menu {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

/* Theme Menu */
.theme-option {
    display: flex;
    align-items: center;
    padding: 10px 12px;
    margin: 4px 0;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    color: var(--text-color);
    background: transparent;
    border: none;
    width: 100%;
    text-align: left;
}

.theme-option:hover {
    background: var(--hover-color);
}

.theme-option.active {
    background: var(--accent-color);
    color: var(--background-color);
}

.theme-color {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    margin-right: 12px;
    border: 2px solid var(--background-color);
    box-shadow: 0 0 0 1px var(--border-color);
    transition: transform 0.2s ease;
}

.theme-option:hover .theme-color {
    transform: scale(1.1);
}

/* Settings Menu */
.settings-section {
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.settings-section:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.settings-section-title {
    font-size: 0.95em;
    color: var(--text-color);
    margin-bottom: 16px;
    font-weight: 600;
    padding-left: 4px;
    text-align: left;
    position: relative;
}

.settings-section-title:after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 24px;
    height: 2px;
    background: var(--accent-color);
    border-radius: 2px;
}

.settings-option {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 12px;
    padding: 6px 8px;
    border-radius: 8px;
    transition: background-color 0.2s ease;
}

.settings-option:last-child {
    margin-bottom: 0;
}

.settings-option:hover {
    background-color: var(--hover-color);
}

.settings-label {
    font-size: 0.9em;
    color: var(--text-color);
    margin-right: 12px;
}

.settings-description {
    font-size: 0.85em;
    color: var(--text-secondary);
    opacity: 0.8;
    margin: -8px 0 16px;
    padding-left: 4px;
    line-height: 1.4;
}

/* Theme Settings */
.theme-section {
    margin-bottom: 16px;
}

.theme-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(100px, 1fr));
    gap: 12px;
    margin-top: 12px;
}

.theme-option {
    padding: 8px;
    border-radius: 8px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.9em;
}

/* Modern Switch Style */
.switch {
    position: relative;
    width: 50px;
    height: 28px;
    margin-left: 16px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
    margin: 0;
    padding: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--border-color);
    transition: .3s ease-in-out;
    border-radius: 28px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 20px;
    width: 20px;
    left: 4px;
    bottom: 4px;
    background-color: var(--background-color);
    transition: .3s ease-in-out;
    border-radius: 50%;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.slider:hover:before {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

input:checked + .slider {
    background-color: var(--accent-color);
}

input:checked + .slider:before {
    transform: translateX(22px);
}

input:focus + .slider {
    box-shadow: 0 0 1px var(--accent-color);
}

/* Settings Toggle Button */
.settings-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    border: 1px solid var(--border-color);
    border-radius: 10px;
    background: transparent;
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.95em;
}

.settings-toggle:hover {
    background: var(--hover-color);
    border-color: var(--text-color);
}

.settings-toggle .dropdown-arrow {
    margin-left: 4px;
    font-size: 0.8em;
    opacity: 0.7;
    transition: transform 0.3s ease;
}

.settings-dropdown.open .settings-toggle {
    background: var(--hover-color);
    border-color: var(--text-color);
}

.settings-dropdown.open .dropdown-arrow {
    transform: rotate(180deg);
}

/* Scheduled Tasks Panel */
.scheduled-tasks-panel {
    margin-top: 20px;
    padding: 20px;
    background: var(--hover-color);
    border-radius: 12px;
    border: 1px solid var(--border-color);
}

.task-input {
    display: flex;
    gap: 12px;
    margin-bottom: 16px;
}

.task-time,
.task-name {
    padding: 10px 14px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--background-color);
    color: var(--text-color);
    font-size: 0.95em;
    transition: all 0.2s ease;
}

.task-time:hover,
.task-name:hover {
    border-color: var(--text-color);
}

.task-time:focus,
.task-name:focus {
    border-color: var(--accent-color);
    outline: none;
}

.task-time {
    width: 130px;
}

.task-name {
    flex: 1;
}

.task-add-btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    background: var(--accent-color);
    color: var(--background-color);
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 0.7em;
    font-weight: 500;
}

.task-add-btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.task-add-btn:active {
    transform: translateY(1px);
}

/* Dropdown Buttons */
.theme-toggle,
.settings-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: transparent;
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 120px;
}

.theme-toggle:hover,
.settings-toggle:hover {
    background: var(--hover-color);
}

.dropdown-arrow {
    margin-left: auto;
    font-size: 0.8em;
    opacity: 0.7;
    transition: transform 0.2s ease;
}

.theme-dropdown.open .dropdown-arrow,
.settings-dropdown.open .dropdown-arrow {
    transform: rotate(180deg);
}

.current-theme-name {
    font-size: 0.95em;
    font-weight: normal;
}

/* Preset Buttons */
.presets {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.preset-btn {
    background-color: var(--preset-color);
    color: var(--text-color);
    border: none;
    border-radius: 16px;
    cursor: pointer;
    padding: 1rem;
    min-width: 100px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px var(--shadow-color);
    position: relative;
}

.preset-btn:hover {
    background-color: var(--preset-hover-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow-color);
}

.preset-btn:active {
    background-color: var(--preset-active-color);
    transform: translateY(0);
}

.preset-time {
    font-size: 1.8rem;
    font-weight: 600;
    line-height: 1;
}

.preset-unit {
    font-size: 0.9rem;
    opacity: 0.8;
}

.preset-btn::after {
    content: attr(data-shortcut);
    position: absolute;
    top: -8px;
    right: -8px;
    font-size: 0.7em;
    background: var(--accent-color);
    color: var(--background-color);
    padding: 2px 6px;
    border-radius: 4px;
    opacity: 0;
    transition: opacity 0.2s;
}

.preset-btn:hover::after {
    opacity: 1;
}

/* Control Buttons */
.control-btn {
    background-color: var(--preset-color);
    color: var(--text-color);
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1rem;
    box-shadow: 0 2px 4px var(--shadow-color);
}

.control-btn:hover {
    background-color: var(--preset-hover-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow-color);
}

.control-btn.primary {
    background-color: var(--success-color);
    color: var(--background-color);
}

.control-btn.primary:hover {
    background-color: var(--accent-color);
    opacity: 0.9;
}

.main-controls {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Progress Bar */
#progress-container {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 6px;
    background: rgba(128, 128, 128, 0.1);
}

#progress-bar {
    height: 100%;
    width: 0;
    background: var(--accent-color);
    transition: width 0.3s linear;
}

/* Fullscreen styles */
:fullscreen #countdown-container {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100vw;
    height: 100vh;
    padding: 1rem;
}

:fullscreen #countdown-display {
    display: flex;
    gap: 4vw;
}

:fullscreen .time-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1vh;
}

:fullscreen .time-section span:not(.label) {
    font-size: 15vw;
    line-height: 1;
}

:fullscreen .time-section .label {
    font-size: 3vw;
    opacity: 0.8;
}

:fullscreen .controls,
:fullscreen .presets,
:fullscreen #progress-bar {
    display: none !important;
}

/* Fullscreen Mode for Mobile */
@media (max-width: 768px) {
    :fullscreen {
        display: flex;
        flex-direction: column;
        justify-content: center;
        background: var(--background-color);
        width: 100vw;
        height: 100vh;
    }

    :fullscreen #countdown-display {
        gap: 2rem;
    }

    :fullscreen .time-section span {
        font-size: calc(min(20vh, 10rem));
    }

    :fullscreen .time-section .label {
        font-size: 1.2rem;
    }

    :fullscreen .controls {
        flex-direction: row;
        justify-content: center;
        gap: 2rem;
        padding: 2rem;
    }

    :fullscreen .presets {
        max-width: 50%;
    }

    :fullscreen .main-controls {
        max-width: 300px;
    }
}

/* Animations */
@keyframes pulse {
    0% { transform: scale(1); filter: brightness(1); }
    50% { transform: scale(1.05); filter: brightness(1.2); }
    100% { transform: scale(1); filter: brightness(1); }
}

@keyframes flash {
    0%, 100% { background-color: var(--background-color); }
    50% { background-color: var(--warning-color); }
}

@keyframes timerComplete {
    0% {
        transform: scale(1);
        opacity: 1;
    }
    25% {
        transform: scale(1.1);
        opacity: 0.8;
    }
    50% {
        transform: scale(1);
        opacity: 1;
    }
    75% {
        transform: scale(1.1);
        opacity: 0.8;
    }
    100% {
        transform: scale(1);
        opacity: 1;
    }
}

.pulse {
    animation: pulse 1s infinite;
}

.flash {
    animation: flash 1s infinite;
}

.timer-complete {
    animation: timerComplete 2s ease-in-out;
}

/* Responsive design */
@media (max-width: 768px) {
    .time-section span {
        font-size: 6rem;
    }
    
    .time-section .label {
        font-size: 1.5rem;
    }
    
    :fullscreen .time-section span {
        font-size: 10rem;
    }
    
    :fullscreen .time-section .label {
        font-size: 2rem;
    }
}

/* Theme selector */
.theme-selector {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.theme-btn {
    background-color: var(--preset-color);
    color: var(--text-color);
    border: none;
    border-radius: 20px;
    cursor: pointer;
    padding: 0.8rem 1.5rem;
    transition: all 0.3s ease;
    font-size: 0.9rem;
    box-shadow: 0 2px 4px var(--shadow-color);
}

.theme-btn:hover {
    background-color: var(--preset-hover-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow-color);
}

.theme-btn.active {
    background-color: var(--primary-color);
    color: white;
}

/* Advanced controls */
.advanced-controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    padding: 2rem;
    background: rgba(var(--primary-color-rgb), 0.05);
    border-radius: 16px;
    margin-top: 2rem;
}

.timer-sequence, .timer-settings {
    text-align: left;
    padding: 1.5rem;
    background: var(--background-color);
    border-radius: 12px;
    box-shadow: 0 2px 8px var(--shadow-color);
}

.timer-sequence h3, .timer-settings h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

#sequence-list {
    min-height: 100px;
    margin: 1rem 0;
    padding: 1rem;
    border: 2px dashed var(--secondary-color);
    border-radius: 8px;
}

.sequence-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.5rem;
    margin-bottom: 0.5rem;
    background: rgba(var(--primary-color-rgb), 0.1);
    border-radius: 6px;
}

.sequence-item button {
    padding: 0.5rem;
    font-size: 0.9rem;
}

.timer-settings label {
    display: block;
    margin-bottom: 1rem;
    cursor: pointer;
}

.volume-control {
    margin-top: 1.5rem;
}

.volume-control input[type="range"] {
    width: 100%;
    margin-top: 0.5rem;
}

.help-panel {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: var(--background-color);
    padding: 1.5rem;
    border-radius: 12px;
    box-shadow: 0 4px 12px var(--shadow-color);
    transform: translateX(120%);
    transition: transform 0.3s ease;
    z-index: 1000;
}

.help-panel.visible {
    transform: translateX(0);
}

.help-panel ul {
    list-style: none;
    text-align: left;
}

.help-panel li {
    margin: 0.5rem 0;
}

#sequence-progress {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--success-color);
    transform-origin: left;
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

/* Custom Time Input */
.custom-time-container {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100px;
    height: 100%;
    background-color: var(--preset-color);
    border-radius: 16px;
    transition: all 0.3s ease;
    box-shadow: 0 2px 4px var(--shadow-color);
    padding: 0.8rem;
}

.custom-time-container:hover {
    background-color: var(--preset-hover-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow-color);
}

.custom-time-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    width: 100%;
    height: 100%;
}

#custom-time-input {
    width: 100%;
    height: 2.2rem;
    border: none;
    background: none;
    color: var(--text-color);
    font-size: 2rem;
    font-weight: 600;
    text-align: center;
    padding: 0;
    margin: 0;
    line-height: 1;
}

#custom-time-input:focus {
    outline: none;
}

#custom-time-input::placeholder {
    color: var(--text-color);
    opacity: 0.6;
    font-size: 1.2rem;
    font-weight: normal;
}

#custom-time-unit {
    border: none;
    background: none;
    color: var(--text-color);
    font-size: 0.9rem;
    font-weight: normal;
    padding: 2px 16px 2px 4px;
    margin-top: 2px;
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 4px center;
    background-size: 12px;
    opacity: 0.8;
    text-align: center;
    text-align-last: center;
}

#custom-time-unit:focus {
    outline: none;
}

/* Remove spinner buttons from number input */
#custom-time-input::-webkit-inner-spin-button,
#custom-time-input::-webkit-outer-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

#custom-time-input[type=number] {
    -moz-appearance: textfield;
}

/* Task List Styles */
.task-list-container {
    margin-top: 12px;
}

.task-header {
    margin-bottom: 16px;
}

.task-add {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background: var(--hover-color);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.task-add:hover {
    background: var(--preset-hover-color);
}

.plus-icon {
    font-size: 1.2em;
    color: var(--accent-color);
    font-weight: 500;
}

.task-form {
    background: var(--background-color);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    margin-top: 16px;
    overflow: hidden;
}

.task-form-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
}

.task-form-header h4 {
    margin: 0;
    font-size: 1em;
    font-weight: 500;
}

.task-form-close {
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 1.5em;
    cursor: pointer;
    padding: 0;
    opacity: 0.6;
    transition: opacity 0.2s ease;
}

.task-form-close:hover {
    opacity: 1;
}

.task-form-content {
    padding: 20px;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.9em;
    color: var(--text-color);
    opacity: 0.8;
}

.form-group input {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--background-color);
    color: var(--text-color);
    font-size: 0.95em;
    transition: all 0.2s ease;
}

.form-group input:hover {
    border-color: var(--text-color);
}

.form-group input:focus {
    border-color: var(--accent-color);
    outline: none;
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-top: 24px;
}

.task-cancel-btn,
.task-confirm-btn {
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 0.95em;
    cursor: pointer;
    transition: all 0.2s ease;
}

.task-cancel-btn {
    background: var(--hover-color);
    border: 1px solid var(--border-color);
    color: var(--text-color);
}

.task-cancel-btn:hover {
    background: var(--preset-hover-color);
}

.task-confirm-btn {
    background: var(--accent-color);
    border: none;
    color: var(--background-color);
}

.task-confirm-btn:hover {
    opacity: 0.9;
}

.task-list {
    margin-top: 16px;
}

.task-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    margin-bottom: 12px;
    background: var(--hover-color);
    border-radius: 10px;
    transition: all 0.2s ease;
}

.task-item:hover {
    background: var(--preset-hover-color);
}

.task-item-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.task-item-time {
    color: var(--accent-color);
    font-weight: 500;
    font-size: 0.95em;
}

.task-item-name {
    color: var(--text-color);
    font-size: 0.95em;
}

.task-item-delete {
    color: var(--text-color);
    background: none;
    border: none;
    cursor: pointer;
    opacity: 0.6;
    transition: opacity 0.2s ease;
    padding: 4px;
    font-size: 1.2em;
}

.task-item-delete:hover {
    opacity: 1;
}

.settings-description {
    color: var(--text-secondary);
    font-size: 0.9em;
    margin-bottom: 1rem;
    line-height: 1.4;
}

.form-help {
    color: var(--text-secondary);
    font-size: 0.8em;
    margin-top: 0.25rem;
    display: block;
}

.task-list {
    margin-top: 1rem;
    max-height: 200px;
    overflow-y: auto;
}

.task-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.5rem;
    margin-bottom: 0.5rem;
    background: var(--background-light);
    border-radius: 4px;
    transition: background-color 0.2s;
}

.task-item:hover {
    background: var(--background-lighter);
}

.task-item-info {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.task-item-time {
    font-weight: 600;
    color: var(--accent-color);
}

.task-item-name {
    font-size: 0.9em;
    color: var(--text-secondary);
}

.shortcut-hint {
    font-size: 0.7em;
    opacity: 0.7;
    background: rgba(255, 255, 255, 0.1);
    padding: 2px 6px;
    border-radius: 4px;
    margin-left: 8px;
    font-family: 'Space Mono', monospace;
}

/* Mobile Responsive Design */
@media (max-width: 768px) {
    .section {
        padding: 3rem 1rem;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .feature-grid,
    .use-case-grid,
    .tips-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

/* Touch Device Optimizations */
@media (hover: none) {
    .preset-btn:hover,
    .control-btn:hover {
        transform: none;
    }

    .preset-btn:active,
    .control-btn:active {
        transform: scale(0.98);
        background-color: var(--hover-color);
    }

    input[type="time"],
    input[type="text"],
    input[type="number"],
    select {
        font-size: 16px !important;
    }

    .control-btn,
    .preset-btn,
    .task-item,
    .theme-option {
        min-height: 44px;
        touch-action: manipulation;
    }
}

/* Mobile Styles */
@media (max-width: 768px) {
    /* 隐藏快捷键提示 */
    .shortcut-hint {
        display: none;
    }

    /* 主题切换按钮样式 */
    .theme-toggle {
        display: flex;
        justify-content: center;
        align-items: center;
        padding: 0.8rem;
        gap: 0.3rem;
    }

    .theme-toggle .current-theme-name,
    .theme-toggle .dropdown-arrow {
        display: inline-block;
        vertical-align: middle;
    }

    .theme-toggle .current-theme-name {
        margin: 0;
        order: 1;
    }

    .theme-toggle .dropdown-arrow {
        margin: 0;
        order: 2;
    }

    /* 调整其他按钮的内边距 */
    .control-btn {
        padding: 0.8rem;
        justify-content: center;
    }
}

/* 文本样式 */
.feature-card h3,
.use-case-content h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--heading-color);
}

.feature-card p,
.use-case-content p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 0;
    font-size: 1.1rem;
}

/* FAQ样式优化 */
.faq-container {
    max-width: 800px;
    margin: 3rem auto 0;
}

details {
    margin-bottom: 1.5rem;
    border: 1px solid rgba(0, 0, 0, 0.1);
}

summary {
    padding: 1.5rem;
    cursor: pointer;
    font-weight: 600;
    color: var(--heading-color);
    list-style: none;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 1.1rem;
}

summary::-webkit-details-marker {
    display: none;
}

summary::after {
    content: '\f107';
    font-family: 'Font Awesome 5 Free';
    font-weight: 900;
    transition: transform 0.3s ease;
    font-size: 1.2rem;
    color: var(--primary-color);
}

details[open] summary::after {
    transform: rotate(180deg);
}

.faq-content {
    padding: 0 1.5rem 1.5rem;
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 1.1rem;
}

/* 页脚样式优化 */
footer {
    padding: 4rem 2rem 2rem;
    background: var(--card-background);
    margin-top: 4rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2.5rem;
}

/* 内容部分样式 */
.content-section {
    margin-top: 0;
    padding-top: 6rem;
    background-color: var(--background-color);
    color: var(--text-color);
    position: relative;
    z-index: 1;
}

/* 每个section的基础样式 */
.section {
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* 标题样式优化 */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
    position: relative;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--heading-color);
    margin-bottom: 1.5rem;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.section-header p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.6;
}

/* 板块标题样式优化 */
.section-header {
    text-align: center;
    margin-bottom: 3.5rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.section-header h2 {
    font-size: 2.2rem;
    font-weight: 700;
    color: var(--heading-color);
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.section-description {
    font-size: 1.2rem;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 600px;
    margin: 0 auto;
}

/* 卡片内容间距优化 */
.feature-card,
.use-case,
.tip-card {
    padding: 2.8rem 2.5rem;
    gap: 1.5rem;
}

.feature-icon {
    margin-bottom: 1.8rem;
}

.feature-card h3,
.use-case-content h3,
.tip-card h3 {
    margin-bottom: 1rem;
    letter-spacing: -0.01em;
}

.feature-card p,
.use-case-content p,
.tip-card p {
    margin-bottom: 1.8rem;
    opacity: 0.9;
}

/* 网格布局优化 */
.feature-grid,
.use-case-grid {
    display: grid;
    gap: 2.5rem;
    margin-top: 3rem;
}

.feature-grid {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}

.use-case-grid {
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

/* 卡片基础样式 */
.feature-card,
.use-case,
details {
    background: var(--card-background);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
}

.feature-card:hover,
.use-case:hover,
details:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

/* 卡片内容样式 */
.feature-icon {
    font-size: 2.8rem;
    margin-bottom: 2rem;
    display: inline-block;
    color: var(--primary-color);
}

.feature-card h3,
.use-case-content h3,
.tip-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--heading-color);
    margin-bottom: 1.2rem;
    line-height: 1.3;
}

.feature-card p,
.use-case-content p,
.tip-card p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

/* 特性列表样式 */
.feature-list {
    list-style: none;
    padding: 0;
    margin: 1.5rem 0 0 0;
}

.feature-list li {
    margin: 0.8rem 0;
    padding-left: 1.8rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.5;
}

.feature-list li::before {
    content: "•";
    color: var(--primary-color);
    font-size: 1.5rem;
    position: absolute;
    left: 0.5rem;
    top: -0.2rem;
}

/* 使用场景卡片样式 */
.use-case-image {
    width: 100%;
    height: 220px;
    object-fit: cover;
    border-radius: 12px;
    margin-bottom: 1.5rem;
}

.use-case-content {
    padding: 0.5rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .use-case {
        padding: 1.5rem;
    }

    .use-case-icon {
        font-size: 2.4rem;
        margin-bottom: 0.8rem;
    }

    .use-case h3 {
        font-size: 1.3rem;
        margin-bottom: 0.6rem;
    }

    .use-case li {
        margin: 0.4rem 0;
        font-size: 0.95rem;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section {
    animation: fadeIn 0.8s ease-out;
}

/* 主题切换过渡 */
* {
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* 添加平滑滚动 */
html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    transition: background-color 0.3s ease;
    overflow-x: hidden;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .section {
        padding: 3rem 1rem;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .feature-grid,
    .use-case-grid,
    .tips-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
}

.hero-section {
    padding: 6rem 2rem;
    text-align: center;
    position: relative;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    color: var(--heading-color);
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.hero-content .lead {
    font-size: 1.25rem;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 600px;
    margin: 0 auto;
}

@media (max-width: 768px) {
    .hero-section {
        padding: 4rem 1.5rem;
    }

    .hero-content h1 {
        font-size: 2.5rem;
    }
    
    .hero-content .lead {
        font-size: 1.1rem;
        padding: 0 1rem;
    }
}

/* 卡片基础样式 */
.feature-card,
.use-case,
.tip-card {
    padding: 2.5rem;
    background: var(--card-background);
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
    overflow: hidden;
}

.feature-card:hover,
.use-case:hover,
.tip-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

/* 卡片内容样式 */
.feature-icon {
    font-size: 2.8rem;
    margin-bottom: 2rem;
    display: inline-block;
    color: var(--primary-color);
}

.feature-card h3,
.use-case-content h3,
.tip-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--heading-color);
    margin-bottom: 1.2rem;
    line-height: 1.3;
}

.feature-card p,
.use-case-content p,
.tip-card p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
    flex-grow: 1;
}

/* 特性列表样式 */
.feature-list {
    list-style: none;
    padding: 0;
    margin: 1.5rem 0 0 0;
}

.feature-list li {
    margin: 0.8rem 0;
    padding-left: 1.8rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.5;
}

.feature-list li::before {
    content: "•";
    color: var(--primary-color);
    font-size: 1.5rem;
    position: absolute;
    left: 0.5rem;
    top: -0.2rem;
}

/* 使用场景卡片样式 */
.use-case-image {
    width: 100%;
    height: 220px;
    object-fit: cover;
    border-radius: 12px;
    margin-bottom: 1.5rem;
}

.use-case-content {
    padding: 0.5rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .feature-card,
    .use-case,
    .tip-card {
        padding: 1.8rem;
    }

    .feature-icon {
        font-size: 2.4rem;
        margin-bottom: 1.5rem;
    }

    .feature-card h3,
    .use-case-content h3,
    .tip-card h3 {
        font-size: 1.3rem;
        margin-bottom: 1rem;
    }

    .feature-card p,
    .use-case-content p,
    .tip-card p {
        font-size: 1rem;
        margin-bottom: 1.2rem;
    }

    .feature-list li {
        font-size: 0.95rem;
        padding-left: 1.5rem;
    }

    .use-case-image {
        height: 180px;
    }
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.2rem;
    margin-top: 1.5rem;
}

.feature-card {
    padding: 1.8rem;
    background: var(--card-background);
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--heading-color);
    margin-bottom: 0.6rem;
    line-height: 1.3;
}

.feature-card p {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 0.8rem;
    opacity: 0.9;
}

.feature-list {
    list-style: none;
    padding: 0;
    margin-top: 0.5rem;
    padding-top: 0.8rem;
    border-top: 1px solid rgba(var(--border-color-rgb), 0.1);
}

.feature-list li {
    margin: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.4;
}

.feature-list li::before {
    content: "✓";
    color: var(--primary-color);
    font-size: 1rem;
    position: absolute;
    left: 0.2rem;
    top: 0;
}

/* 核心功能板块样式优化 */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
    margin-top: 1.2rem;
    max-width: 1000px;
    margin-left: auto;
    margin-right: auto;
}

.feature-card {
    padding: 1.5rem;
    background: var(--card-background);
    border-radius: 12px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.feature-icon {
    font-size: 1.8rem;
    margin-bottom: 0.8rem;
    color: var(--primary-color);
}

.feature-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--heading-color);
    margin-bottom: 0.4rem;
    line-height: 1.3;
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.4;
    margin-bottom: 0.6rem;
    opacity: 0.9;
}

.feature-list {
    list-style: none;
    padding: 0;
    margin-top: 0.4rem;
    padding-top: 0.6rem;
    border-top: 1px solid rgba(var(--border-color-rgb), 0.08);
}

.feature-list li {
    margin: 0.3rem 0;
    padding-left: 1.2rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 0.9rem;
    line-height: 1.4;
}

.feature-list li::before {
    content: "✓";
    color: var(--primary-color);
    font-size: 0.9rem;
    position: absolute;
    left: 0;
    top: 0;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 0.8rem;
        margin-top: 1rem;
        padding: 0 1rem;
    }

    .feature-card {
        padding: 1.2rem;
    }

    .feature-icon {
        font-size: 1.6rem;
        margin-bottom: 0.6rem;
    }

    .feature-card h3 {
        font-size: 1.1rem;
        margin-bottom: 0.3rem;
    }

    .feature-list {
        margin-top: 0.3rem;
        padding-top: 0.5rem;
    }

    .feature-list li {
        margin: 0.25rem 0;
    }
}

.feature-card {
    padding: 1.6rem;
    background: var(--card-background);
    border-radius: 12px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 0.9rem;
    color: var(--primary-color);
}

.feature-card h3 {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--heading-color);
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.feature-card p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 0.8rem;
    opacity: 0.9;
}

.feature-list {
    list-style: none;
    padding: 0;
    margin-top: 0.5rem;
    padding-top: 0.7rem;
    border-top: 1px solid rgba(var(--border-color-rgb), 0.08);
}

.feature-list li {
    margin: 0.4rem 0;
    padding-left: 1.3rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.5;
}

.feature-list li::before {
    content: "✓";
    color: var(--primary-color);
    font-size: 1rem;
    position: absolute;
    left: 0;
    top: 0;
}

.feature-list {
    list-style: none;
    padding: 0;
    margin-top: 0.3rem;
    padding-top: 0.5rem;
    border-top: 1px solid rgba(var(--border-color-rgb), 0.08);
}

.feature-list li {
    margin: 0.2rem 0;
    padding-left: 1.3rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.4;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.tip-card {
    padding: 1.8rem;
    background: var(--card-background);
    border-radius: 14px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
}

.tip-icon {
    font-size: 2.4rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.tip-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--heading-color);
    margin-bottom: 0.8rem;
    line-height: 1.3;
}

.tip-card p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 1rem;
    opacity: 0.9;
}

.tip-list {
    list-style: none;
    padding: 0;
    margin: 0;
    padding-left: 0.5rem;
}

.tip-list li {
    margin: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.5;
}

.tip-list li::before {
    content: "✓";
    color: var(--primary-color);
    font-size: 1.1rem;
    position: absolute;
    left: 0.2rem;
    top: 0;
}

@media (max-width: 768px) {
    .tips-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
        padding: 0 1rem;
    }

    .tip-card {
        padding: 1.5rem;
    }

    .tip-icon {
        font-size: 2.2rem;
        margin-bottom: 0.8rem;
    }

    .tip-card h3 {
        font-size: 1.3rem;
        margin-bottom: 0.6rem;
    }

    .tip-list li {
        margin: 0.4rem 0;
        font-size: 0.95rem;
    }
}

.use-case-icon {
    font-size: 2rem;
    margin-bottom: 2.3rem;
    color: var(--primary-color);
    display: inline-block;
}

.use-case h3 {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--heading-color);
    margin-bottom: 0.3rem;
    line-height: 1.3;
}

.use-case p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 0.7rem;
    opacity: 0.9;
}

@media (max-width: 768px) {
    .use-case h3 {
        font-size: 1.3rem;
        margin-bottom: 0.2rem;
    }

    .use-case p {
        margin-bottom: 0.6rem;
    }
}

.tip-card h3 {
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--heading-color);
    margin-bottom: 0.3rem;
    line-height: 1.3;
}

.tip-card p {
    font-size: 1.05rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 0.7rem;
    opacity: 0.9;
}

.tip-list {
    list-style: none;
    padding: 0;
    margin: 0;
    padding-left: 0.5rem;
}

.tip-list li {
    margin: 0.2rem 0;
    padding-left: 1.3rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.4;
}

.tip-list li::before {
    content: "✓";
    color: var(--primary-color);
    font-size: 1rem;
    position: absolute;
    left: 0.2rem;
    top: 0;
}

@media (max-width: 768px) {
    .tip-card h3 {
        font-size: 1.3rem;
        margin-bottom: 0.2rem;
    }

    .tip-card p {
        margin-bottom: 0.6rem;
    }

    .tip-list li {
        margin: 0.15rem 0;
        font-size: 0.95rem;
    }
}

.feature-icon,
.use-case-icon,
.tip-icon {
    color: var(--primary-color);
    display: inline-block;
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 0.9rem;
}

.use-case-icon {
    font-size: 2rem;
    margin-bottom: 2.3rem;
}

.tip-icon {
    font-size: 2.4rem;
    margin-bottom: 1rem;
}

@media (max-width: 768px) {
    .feature-icon {
        font-size: 1.8rem;
        margin-bottom: 0.8rem;
    }

    .use-case-icon {
        font-size: 1.8rem;
        margin-bottom: 1.6rem;
    }

    .tip-icon {
        font-size: 2.2rem;
        margin-bottom: 0.8rem;
    }
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    display: inline-block;
    color: var(--primary-color);
}

@media (max-width: 768px) {
    .feature-icon {
        font-size: 1.8rem;
        margin-bottom: 1.2rem;
    }
}

.duration-input {
    display: flex;
    gap: 10px;
    align-items: center;
}

.task-duration {
    width: 80px;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--input-bg);
    color: var(--text-color);
    font-size: 0.95em;
    transition: all 0.2s ease;
}

.task-duration:hover {
    border-color: var(--text-color);
}

.task-duration:focus {
    border-color: var(--accent-color);
    outline: none;
}

#taskDurationUnit {
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--input-bg);
    color: var(--text-color);
    font-size: 0.95em;
    transition: all 0.2s ease;
}

#taskDurationUnit:hover {
    border-color: var(--text-color);
}

#taskDurationUnit:focus {
    border-color: var(--accent-color);
    outline: none;
}

.task-item-duration {
    font-size: 0.9em;
    color: var(--text-secondary);
    margin: 0 10px;
}

.task-form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 10px;
    margin-top: 20px;
}

.btn-cancel, .btn-confirm {
    padding: 8px 16px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 500;
    transition: background-color 0.2s;
}

.btn-cancel {
    background: var(--button-secondary-bg);
    color: var(--text-color);
}

.btn-cancel:hover {
    background: var(--button-secondary-hover);
}

.btn-confirm {
    background: var(--primary-color);
    color: white;
}

.btn-confirm:hover {
    background: var(--primary-color-hover);
    opacity: 0.9;
}

/* FAQ部分样式 */
.faq-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    padding: 2rem 0;
}

.faq-item {
    background: var(--card-bg);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.faq-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.faq-item h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.2rem;
    font-weight: 600;
}

.faq-item p {
    color: var(--text-color);
    line-height: 1.6;
    margin: 0;
    font-size: 0.95rem;
}

@media (max-width: 768px) {
    .faq-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
        padding: 1rem 0;
    }

    .faq-item {
        padding: 1.2rem;
    }

    .faq-item h3 {
        font-size: 1.1rem;
    }
}