/* ============================================
   小悟学伴 - 暖色调极简风格 v4.0
   配色：暖奶米白 + 暖驼金 + 四组马卡龙辅助色
   ============================================ */

:root {
    /* === 暖色基底 === */
    --warm-white: #FBF9F6;
    --warm-bg: #FAF8F3;
    --warm-card: #FFFFFF;
    --warm-section: #F8F5F0;

    /* === 品牌色：暖驼金 === */
    --brand: #C9A96E;
    --brand-light: #DFC99A;
    --brand-dark: #B8956A;

    /* === 辅助区分色（4组，仅用于卡片图标圆形底） === */
    --accent-yellow: #FDF6E3;
    --accent-blue: #E8F4FD;
    --accent-green: #E6F7EE;
    --accent-purple: #F5EEF8;

    /* === 文字 === */
    --text-primary: #3D3D3D;
    --text-secondary: #999999;
    --text-muted: #BBBBBB;
    --text-decorative: #C9B8D4;

    /* === 描边 / 阴影 === */
    --border-light: #EDE9E3;
    --border-medium: #E0DAD2;
    --shadow-card: inset 0 1px 3px rgba(0,0,0,0.02), 0 1px 2px rgba(0,0,0,0.03);
    --shadow-card-hover: 0 8px 28px rgba(0,0,0,0.07);
    --shadow-btn: 0 4px 14px rgba(201, 169, 110, 0.25);
    --shadow-mockup: 0 20px 60px rgba(0,0,0,0.10), 0 8px 24px rgba(0,0,0,0.06);

    /* === 圆角 === */
    --radius-card: 16px;
    --radius-btn: 14px;
    --radius-sm: 10px;
    --radius-full: 9999px;

    /* === 过渡 === */
    --transition: 250ms ease;
}

/* ============================================
   基础重置
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--warm-white);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1360px;
    margin: 0 auto;
    padding: 0 32px;
}

.hidden {
    display: none !important;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ============================================
   导航栏
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(251, 249, 246, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-light);
    height: 64px;
}

.header .container {
    display: flex;
    align-items: center;
    height: 64px;
    max-width: 100%;
    padding: 0 32px;
}

.logo-link {
    text-decoration: none;
    flex-shrink: 0;
}

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

.logo-img {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-sm);
    object-fit: contain;
}

.logo-text {
    display: flex;
    flex-direction: column;
}

.logo-text h1 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.01em;
    line-height: 1.2;
}

.logo-text .tagline {
    font-size: 0.65rem;
    color: var(--text-decorative);
    font-weight: 500;
    line-height: 1;
}

/* 导航包装器 */
.nav-wrapper {
    display: flex;
    align-items: center;
    flex: 1;
    justify-content: center;
    margin-left: 12px;
    position: relative;
}

.nav {
    display: flex;
    align-items: center;
    gap: 2px;
}

.nav-link {
    padding: 8px 16px;
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    border-radius: var(--radius-btn);
    transition: var(--transition);
    white-space: nowrap;
}

.nav-link:hover {
    color: var(--brand);
    background: rgba(201, 169, 110, 0.08);
}

/* 用户操作区 */
.header-actions {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-shrink: 0;
    position: absolute;
    right: 0;
    top: 50%;
    transform: translateY(-50%);
}

.btn-download-header {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 20px;
    background: var(--brand);
    color: #fff;
    border: none;
    border-radius: var(--radius-btn);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: var(--transition);
    white-space: nowrap;
}

.btn-download-header:hover {
    background: var(--brand-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-btn);
}

/* 汉堡菜单按钮 */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 10px 8px;
    border: none;
    background: none;
    cursor: pointer;
    z-index: 1001;
}

.nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s;
}

.nav-toggle.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}
.nav-toggle.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ============================================
   Hero 区域
   ============================================ */
.hero {
    padding: 120px 0 80px;
    background: var(--warm-white);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -30%;
    right: -5%;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(201, 169, 110, 0.10) 0%, transparent 65%);
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -20%;
    left: -5%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(201, 169, 110, 0.07) 0%, transparent 65%);
    pointer-events: none;
}

.hero .container {
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
    gap: 60px;
    max-width: 100%;
    padding: 0 60px;
}

.hero-content {
    flex: 0 1 auto;
    width: 420px;
    max-width: 520px;
    text-align: left;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    background: rgba(201, 169, 110, 0.10);
    border: 1px solid rgba(201, 169, 110, 0.20);
    border-radius: var(--radius-full);
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--brand-dark);
    margin-bottom: 24px;
}

.hero-title {
    margin-bottom: 12px;
}

.hero-title .title-line {
    display: block;
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.15;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.hero-title .title-line .hl-m {
    color: var(--brand);
}
.hero-title .title-line .hl-t {
    color: var(--brand);
}
.hero-title .title-line .hl-l {
    color: var(--brand);
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-decorative);
    font-weight: 500;
    margin-bottom: 10px;
    letter-spacing: 0.02em;
}

.hero-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    max-width: 500px;
    line-height: 1.7;
    margin-bottom: 28px;
}

.hero-actions {
    display: flex;
    gap: 12px;
    align-items: center;
    justify-content: flex-start;
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    background: var(--brand);
    color: #fff;
    text-decoration: none;
    border: none;
    border-radius: var(--radius-btn);
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-btn);
}

.btn-primary:hover {
    background: var(--brand-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(201, 169, 110, 0.35);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    background: transparent;
    color: var(--text-primary);
    text-decoration: none;
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-btn);
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
}

.btn-secondary:hover {
    border-color: var(--brand-light);
    color: var(--brand-dark);
    background: rgba(201, 169, 110, 0.05);
}

/* Hero 设备 Mockup */
.hero-visual {
    flex: 0 1 auto;
    width: 100%;
    max-width: 1000px;
}

.device-mockup {
    position: relative;
    background: #fff;
    border-radius: 20px;
    box-shadow: var(--shadow-mockup);
    overflow: hidden;
    border: 1px solid var(--border-light);
}

.device-mockup .mockup-topbar {
    height: 32px;
    background: var(--warm-section);
    display: flex;
    align-items: center;
    padding: 0 16px;
    gap: 8px;
    border-bottom: 1px solid var(--border-light);
}

.device-mockup .mockup-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--border-medium);
}

.device-mockup .mockup-dot:nth-child(1) {
    background: #F87171;
}
.device-mockup .mockup-dot:nth-child(2) {
    background: #FBBF24;
}
.device-mockup .mockup-dot:nth-child(3) {
    background: #34D399;
}

.device-mockup .mockup-screen {
    width: 100%;
    height: auto;
    display: block;
}

/* ============================================
   通用 Section 头
   ============================================ */
.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(201, 169, 110, 0.10);
    color: var(--brand-dark);
    font-size: 0.8rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    margin-bottom: 12px;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
    letter-spacing: -0.01em;
}

.section-subtitle {
    font-size: 1rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   两大核心模式
   ============================================ */
.modes-section {
    padding: 80px 0;
    background: var(--warm-bg);
}

.mode-panels {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 40px;
}

.mode-panel {
    background: var(--warm-card);
    border-radius: var(--radius-card);
    padding: 36px 32px;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-card);
    transition: var(--transition);
}

.mode-panel:hover {
    box-shadow: var(--shadow-card-hover);
    transform: translateY(-3px);
}

.mode-panel-header {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    margin-bottom: 24px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-light);
}

.mode-panel-icon {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.mode-panel-icon svg {
    width: 24px;
    height: 24px;
    stroke: var(--brand-dark);
    stroke-width: 1.8;
    fill: none;
}

.mode-panel-icon.is-blue {
    background: var(--accent-blue);
}
.mode-panel-icon.is-purple {
    background: var(--accent-purple);
}

.mode-panel-header h3 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.mode-subtitle {
    font-size: 0.85rem;
    color: var(--brand-dark);
    font-weight: 500;
}

.mode-features {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.mode-features li {
    display: flex;
    gap: 12px;
    align-items: flex-start;
}

.mode-features .check-icon {
    flex-shrink: 0;
    width: 20px;
    height: 20px;
    margin-top: 2px;
}

.mode-features .check-icon svg {
    width: 20px;
    height: 20px;
    stroke: var(--brand);
    stroke-width: 2.5;
    fill: none;
}

.mode-features li > div strong {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 2px;
}

.mode-features li > div span {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* 通用功能条 */
.gen-features {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.gen-feature {
    background: var(--warm-card);
    border-radius: var(--radius-btn);
    padding: 20px 16px;
    text-align: center;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-card);
    transition: var(--transition);
}

.gen-feature:hover {
    box-shadow: var(--shadow-card-hover);
    transform: translateY(-2px);
}

.gen-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 10px;
}

.gen-icon svg {
    width: 20px;
    height: 20px;
    stroke: var(--brand-dark);
    stroke-width: 1.8;
    fill: none;
}

.gen-icon.is-yellow {
    background: var(--accent-yellow);
}
.gen-icon.is-blue {
    background: var(--accent-blue);
}
.gen-icon.is-green {
    background: var(--accent-green);
}
.gen-icon.is-purple {
    background: var(--accent-purple);
}

.gen-feature h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.gen-feature p {
    font-size: 0.75rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

/* ============================================
   使用步骤 — 垂直时间线
   ============================================ */
.steps-section {
    padding: 80px 0;
    background: var(--warm-white);
}

.timeline {
    position: relative;
    max-width: 720px;
    margin: 0 auto;
    padding-left: 20px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 44px;
    top: 18px;
    bottom: 18px;
    width: 2px;
    background: var(--border-medium);
}

.timeline-item {
    display: flex;
    gap: 28px;
    padding-bottom: 32px;
    position: relative;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-marker {
    flex-shrink: 0;
    width: 48px;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.timeline-num {
    width: 36px;
    height: 36px;
    background: var(--brand);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    font-weight: 700;
    position: relative;
    z-index: 1;
    box-shadow: 0 2px 8px rgba(201, 169, 110, 0.25);
}

.timeline-content {
    flex: 1;
    padding-top: 6px;
}

.timeline-content h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.timeline-content p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ============================================
   产品界面预览 — 3列截图展示
   ============================================ */
.preview-section {
    padding: 80px 0;
    background: var(--warm-section);
}

.preview-section .container {
    max-width: 100%;
    padding: 0 60px;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    max-width: 2000px;
    margin: 0 auto;
}

.preview-card {
    background: var(--warm-card);
    border-radius: var(--radius-card);
    overflow: hidden;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-card);
    transition: var(--transition);
}

.preview-card:hover {
    box-shadow: var(--shadow-card-hover);
    transform: translateY(-4px);
}

.preview-device {
    width: 100%;
    overflow: hidden;
    background: #fff;
    position: relative;
}

.preview-device .preview-topbar {
    height: 28px;
    background: var(--warm-section);
    display: flex;
    align-items: center;
    padding: 0 14px;
    gap: 6px;
    border-bottom: 1px solid var(--border-light);
}

.preview-device .preview-topbar span {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--border-medium);
}
.preview-device .preview-topbar span:nth-child(1) { background: #F87171; }
.preview-device .preview-topbar span:nth-child(2) { background: #FBBF24; }
.preview-device .preview-topbar span:nth-child(3) { background: #34D399; }

.preview-device img {
    width: 100%;
    height: auto;
    display: block;
}

.preview-body {
    padding: 20px 24px 24px;
    text-align: center;
}

.preview-body h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.preview-body p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.preview-body .preview-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    justify-content: center;
    margin-top: 12px;
}

.preview-body .preview-tags span {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(201, 169, 110, 0.08);
    color: var(--brand-dark);
    font-size: 0.72rem;
    font-weight: 500;
    border-radius: var(--radius-full);
}

/* ============================================
   产品特色（文案卡片）
   ============================================ */
.usp-section {
    padding: 80px 0;
    background: var(--warm-white);
}

.usp-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.usp-card {
    background: var(--warm-card);
    border-radius: var(--radius-card);
    padding: 36px 24px;
    text-align: center;
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-card);
    transition: var(--transition);
}

.usp-card:hover {
    box-shadow: var(--shadow-card-hover);
    transform: translateY(-4px);
}

.usp-icon {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 18px;
}

.usp-icon svg {
    width: 26px;
    height: 26px;
    stroke: var(--brand-dark);
    stroke-width: 1.8;
    fill: none;
}

.usp-icon.i-target {
    background: var(--accent-blue);
}
.usp-icon.i-human {
    background: var(--accent-green);
}
.usp-icon.i-heart {
    background: var(--accent-purple);
}
.usp-icon.i-brain {
    background: var(--accent-yellow);
}

.usp-card h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.usp-card p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ============================================
   页脚
   ============================================ */
.footer {
    padding: 32px 0;
    background: var(--warm-section);
    border-top: 1px solid var(--border-light);
    text-align: center;
}

.footer p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ============================================
   通知（兼容 shared/components.js）
   ============================================ */
.notification-bar {
    position: fixed;
    top: 80px;
    right: 24px;
    z-index: 9999;
    padding: 14px 24px;
    border-radius: var(--radius-btn);
    font-size: 0.9rem;
    font-weight: 500;
    box-shadow: var(--shadow-card-hover);
    animation: notifSlideIn 0.3s ease;
    max-width: 360px;
}

.notification-bar.success {
    background: var(--accent-green);
    color: #2D6A4F;
    border: 1px solid #B7E4C7;
}
.notification-bar.error {
    background: #FEE2E2;
    color: #991B1B;
    border: 1px solid #FECACA;
}
.notification-bar.info {
    background: var(--accent-blue);
    color: #1E4A6B;
    border: 1px solid #BAE6FD;
}
.notification-bar.warning {
    background: var(--accent-yellow);
    color: #7A5A00;
    border: 1px solid #FDE68A;
}

@keyframes notifSlideIn {
    from {
        transform: translateX(120%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* ============================================
   响应式
   ============================================ */
@media (max-width: 1024px) {
    .hero-desc {
        max-width: 100%;
        margin: 0 auto 28px;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-visual {
        min-width: 0;
        max-width: 480px;
        width: 100%;
    }

    .hero-title .title-line {
        font-size: 2.4rem;
    }

    .mode-panels {
        grid-template-columns: 1fr;
    }

    .preview-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .usp-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .gen-features {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-wrapper {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: rgba(251, 249, 246, 0.98);
        backdrop-filter: blur(12px);
        border-bottom: 1px solid var(--border-light);
        padding: 8px 16px 16px;
        gap: 0;
        margin-left: 0;
        box-shadow: 0 8px 24px rgba(0, 0, 0, 0.06);
    }

    .nav-wrapper.open {
        display: flex;
    }

    .nav-wrapper .nav {
        flex-direction: column;
        width: 100%;
        gap: 2px;
    }

    .nav-wrapper .header-actions {
        position: static;
        transform: none;
        flex-direction: column;
        width: 100%;
        gap: 4px;
        margin-top: 8px;
        padding-top: 8px;
        border-top: 1px solid var(--border-light);
    }

    .nav-link {
        width: 100%;
        padding: 12px 16px;
        font-size: 0.95rem;
    }

    .btn-download-header {
        width: 100%;
        justify-content: center;
    }

    .hero {
        padding: 100px 0 60px;
    }

    .hero-title .title-line {
        font-size: 1.8rem;
    }

    .hero-subtitle {
        font-size: 0.95rem;
    }

    .hero .container {
        flex-direction: column;
        text-align: center;
        gap: 32px;
    }

    .hero-content {
        width: 100%;
        text-align: center;
    }

    .hero-desc {
        margin: 0 auto 28px;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-visual {
        min-width: 0;
        max-width: 360px;
        width: 100%;
    }

    .hero-actions {
        flex-direction: column;
        align-items: stretch;
    }

    .hero-actions a,
    .hero-actions button {
        justify-content: center;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .section-header {
        margin-bottom: 32px;
    }

    .mode-panels {
        gap: 16px;
    }

    .mode-panel {
        padding: 24px 20px;
    }

    .preview-grid {
        max-width: 100%;
        grid-template-columns: 1fr;
    }

    .usp-grid {
        grid-template-columns: 1fr;
    }

    .gen-features {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .timeline {
        padding-left: 0;
    }

    .timeline::before {
        left: 28px;
    }

    .timeline-marker {
        width: 40px;
    }

    .timeline-num {
        width: 32px;
        height: 32px;
        font-size: 0.8rem;
    }

    .steps-section {
        padding: 60px 0;
    }
}