/* ===== 全局样式 ===== */
:root {
    --primary-color: #50A87B;
    --primary-gradient: linear-gradient(135deg, #50A87B 0%, #3D8A63 100%);
    --secondary-gradient: linear-gradient(135deg, #50A87B 0%, #2D6B4F 100%);
    --accent-color: #50A87B;
    --accent-hover: #3D8A63;
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a24;
    --bg-card: rgba(26, 26, 36, 0.8);
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.8);
    --text-tertiary: rgba(255, 255, 255, 0.6);
    --border-color: rgba(255, 255, 255, 0.1);
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 10px 40px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(80, 168, 123, 0.3);
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* 粒子背景 */
#particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--accent-color);
    border-radius: 50%;
    opacity: 0.3;
    animation: float 20s infinite ease-in-out;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) translateX(0) scale(1);
        opacity: 0.3;
    }
    50% {
        transform: translateY(-100px) translateX(50px) scale(1.5);
        opacity: 0.6;
    }
}

/* ===== 导航栏 ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1.25rem 0;
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

.navbar.scrolled {
    padding: 0.75rem 0;
    background: rgba(10, 10, 15, 0.95);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    text-decoration: none;
}

.logo-icon {
    width: 40px;
    height: 40px;
    object-fit: contain;
    padding: 4px;
    background: rgba(80, 168, 123, 0.1);
    border: 1px solid rgba(80, 168, 123, 0.3);
    border-radius: 10px;
    transition: all var(--transition-base);
}

.logo:hover .logo-icon {
    background: var(--primary-gradient);
    border-color: transparent;
    box-shadow: 0 0 20px rgba(80, 168, 123, 0.4);
}

.logo-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-gradient);
    transition: width var(--transition-base);
}

.nav-link:hover {
    color: var(--text-primary);
}

.nav-link:hover::after {
    width: 100%;
}

.nav-link-login {
    padding: 0.5rem 1.25rem;
    background: transparent;
    border: 1px solid var(--accent-color);
    color: var(--accent-color) !important;
    border-radius: 20px;
    font-size: 0.875rem;
    transition: all var(--transition-base);
}

.nav-link-login:hover {
    background: var(--primary-gradient);
    color: white !important;
    border-color: transparent;
}

.nav-link-login::after {
    display: none;
}

.nav-cta {
    padding: 0.75rem 1.5rem;
    background: var(--primary-gradient);
    color: white;
    text-decoration: none;
    border-radius: 30px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: all var(--transition-base);
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-glow);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: all var(--transition-fast);
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding: 8rem 2rem 6rem;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -30%;
    width: 80%;
    height: 100%;
    background: radial-gradient(circle, rgba(102, 126, 234, 0.15) 0%, transparent 70%);
    filter: blur(100px);
    animation: moveBackground 15s infinite alternate;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -50%;
    left: -30%;
    width: 80%;
    height: 100%;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.1) 0%, transparent 70%);
    filter: blur(100px);
    animation: moveBackground 15s infinite alternate-reverse;
}

@keyframes moveBackground {
    0% {
        transform: translate(0, 0) scale(1);
    }
    100% {
        transform: translate(30px, 30px) scale(1.1);
    }
}

.hero-content {
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-left {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--accent-color);
    width: fit-content;
    animation: fadeInUp 0.8s 0.2s both;
}

.badge-icon {
    font-size: 1rem;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 3.8rem);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

.title-line {
    display: block;
    opacity: 0;
    transform: translateY(30px);
    animation: fadeInUp 0.8s both;
}

.title-line:nth-child(1) {
    animation-delay: 0.4s;
}

.title-line:nth-child(2) {
    animation-delay: 0.6s;
    font-size: 0.9em;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.gradient-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    line-height: 1.8;
    opacity: 0;
    animation: fadeInUp 0.8s 0.8s both;
}

.hero-stats {
    display: flex;
    gap: 3rem;
    opacity: 0;
    animation: fadeInUp 0.8s 1s both;
}

.hero-stat {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-text {
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    opacity: 0;
    animation: fadeInUp 0.8s 1.2s both;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 2rem;
    border-radius: 16px;
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 60px rgba(102, 126, 234, 0.5);
}

.btn-apple {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-color);
    backdrop-filter: blur(10px);
}

.btn-apple:hover {
    background: var(--glass-bg);
    border-color: var(--accent-color);
    transform: translateY(-3px);
}

.btn-large {
    padding: 1.25rem 2rem;
    min-width: 240px;
}

.btn-download {
    padding: 1rem 1.5rem;
    min-width: 200px;
}

.btn-icon {
    width: 28px;
    height: 28px;
}

.btn-content {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.25rem;
}

.btn-title {
    font-size: 1rem;
    font-weight: 600;
    line-height: 1.2;
}

.btn-subtitle {
    font-size: 0.75rem;
    opacity: 0.8;
    font-weight: 400;
}

/* 手机展示 */
.hero-right {
    display: flex;
    justify-content: center;
    align-items: center;
    perspective: 1000px;
}

.phone-mockup {
    position: relative;
    animation: floatPhone 6s infinite ease-in-out;
}

@keyframes floatPhone {
    0%, 100% {
        transform: translateY(0) rotateX(5deg) rotateY(-5deg);
    }
    50% {
        transform: translateY(-20px) rotateX(5deg) rotateY(-5deg);
    }
}

.phone-frame {
    width: 320px;
    height: 650px;
    background: linear-gradient(145deg, #2a2a3a, #1a1a24);
    border-radius: 40px;
    padding: 12px;
    box-shadow:
        0 50px 100px rgba(0, 0, 0, 0.5),
        0 0 60px rgba(80, 168, 123, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.1);
    position: relative;
}

.phone-notch {
    position: absolute;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 28px;
    background: #000;
    border-radius: 20px;
    z-index: 10;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.phone-screen {
    width: 100%;
    height: 100%;
    background: var(--bg-secondary);
    border-radius: 32px;
    overflow: hidden;
    position: relative;
}

.phone-screenshot {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: top;
    border-radius: 28px;
}

/* 下雪特效 */
.phone-screen {
    position: relative;
    overflow: hidden;
}

/* 雪花动画层 - 更飘逸更细腻的下雪效果 */
.snow-fall-layer {
    position: absolute !important;
    top: 0 !important;
    left: 0 !important;
    width: 100% !important;
    height: 100% !important;
    pointer-events: none;
    z-index: 10 !important;
    overflow: hidden;
}

/* 大雪花 - 更大更明显，随机分布 */
.snow-fall-layer::before {
    content: '';
    position: absolute;
    width: 400%;
    height: 400%;
    top: -150%;
    left: -50%;
    background-image: 
        radial-gradient(10px 10px at 15px 25px, #ffffff, transparent),
        radial-gradient(12px 12px at 85px 55px, #ffffff, transparent),
        radial-gradient(10px 10px at 145px 95px, #ffffff, transparent),
        radial-gradient(11px 11px at 205px 125px, #ffffff, transparent),
        radial-gradient(10px 10px at 265px 175px, #ffffff, transparent),
        radial-gradient(12px 12px at 325px 215px, #ffffff, transparent),
        radial-gradient(10px 10px at 385px 265px, #ffffff, transparent),
        radial-gradient(11px 11px at 445px 305px, #ffffff, transparent),
        radial-gradient(10px 10px at 505px 355px, #ffffff, transparent),
        radial-gradient(12px 12px at 565px 395px, #ffffff, transparent),
        radial-gradient(10px 10px at 625px 445px, #ffffff, transparent),
        radial-gradient(11px 11px at 685px 485px, #ffffff, transparent),
        radial-gradient(10px 10px at 745px 535px, #ffffff, transparent),
        radial-gradient(12px 12px at 805px 575px, #ffffff, transparent),
        radial-gradient(10px 10px at 55px 625px, #ffffff, transparent),
        radial-gradient(11px 11px at 125px 665px, #ffffff, transparent),
        radial-gradient(10px 10px at 195px 715px, #ffffff, transparent),
        radial-gradient(12px 12px at 265px 755px, #ffffff, transparent),
        radial-gradient(10px 10px at 335px 805px, #ffffff, transparent),
        radial-gradient(11px 11px at 405px 845px, #ffffff, transparent),
        radial-gradient(10px 10px at 475px 895px, #ffffff, transparent),
        radial-gradient(12px 12px at 545px 935px, #ffffff, transparent),
        radial-gradient(10px 10px at 615px 985px, #ffffff, transparent),
        radial-gradient(11px 11px at 685px 1025px, #ffffff, transparent),
        radial-gradient(10px 10px at 755px 1075px, #ffffff, transparent),
        radial-gradient(12px 12px at 825px 1115px, #ffffff, transparent),
        radial-gradient(10px 10px at 35px 1165px, #ffffff, transparent),
        radial-gradient(11px 11px at 115px 1205px, #ffffff, transparent),
        radial-gradient(10px 10px at 185px 1255px, #ffffff, transparent),
        radial-gradient(12px 12px at 255px 1295px, #ffffff, transparent);
    background-repeat: repeat;
    background-size: 850px 1350px;
    animation: snow-slow 50s linear infinite;
    opacity: 0.95;
}

/* 中雪花 - 不同位置，增加随机感 */
.snow-fall-layer::after {
    content: '';
    position: absolute;
    width: 400%;
    height: 400%;
    top: -150%;
    left: -50%;
    background-image: 
        radial-gradient(8px 8px at 45px 35px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 95px 85px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 165px 115px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 225px 165px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 285px 205px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 345px 255px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 415px 295px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 475px 345px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 535px 385px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 595px 435px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 655px 475px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 715px 525px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 775px 565px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 835px 615px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 895px 655px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 75px 705px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 135px 745px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 195px 795px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 255px 835px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 315px 885px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 375px 925px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 435px 975px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 495px 1015px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 555px 1065px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 615px 1105px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 675px 1145px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 735px 1195px, rgba(255,255,255,0.9), transparent),
        radial-gradient(7px 7px at 795px 1235px, rgba(255,255,255,0.9), transparent),
        radial-gradient(8px 8px at 855px 1285px, rgba(255,255,255,0.9), transparent);
    background-size: 950px 1350px;
    animation: snow-slow 45s linear infinite;
    animation-delay: -25s;
    opacity: 0.85;
}

/* 小雪花 - 微小细节，随机分布 */
.snow-tiny {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    overflow: hidden;
}

.snow-tiny::before {
    content: '';
    position: absolute;
    width: 400%;
    height: 400%;
    top: -150%;
    left: -50%;
    background-image: 
        radial-gradient(5px 5px at 25px 15px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 75px 65px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 135px 105px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 195px 155px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 255px 195px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 315px 245px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 375px 285px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 435px 335px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 495px 375px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 555px 425px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 615px 465px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 675px 515px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 735px 555px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 795px 605px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 855px 645px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 915px 695px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 45px 745px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 105px 785px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 165px 835px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 225px 875px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 285px 925px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 345px 965px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 405px 1015px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 465px 1055px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 525px 1105px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 585px 1145px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 645px 1195px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 705px 1235px, rgba(255,255,255,0.75), transparent),
        radial-gradient(5px 5px at 765px 1285px, rgba(255,255,255,0.75), transparent),
        radial-gradient(6px 6px at 825px 1325px, rgba(255,255,255,0.75), transparent);
    background-size: 950px 1400px;
    animation: snow-slow 55s linear infinite;
    animation-delay: -35s;
    opacity: 0.75;
}

/* 飘落动画 - 更慢更不规则 */
@keyframes snow-slow {
    0% {
        transform: translateX(0) translateY(0);
    }
    25% {
        transform: translateX(-50px) translateY(337px);
    }
    50% {
        transform: translateX(40px) translateY(675px);
    }
    75% {
        transform: translateX(-60px) translateY(1012px);
    }
    100% {
        transform: translateX(30px) translateY(1350px);
    }
}

.app-header {
    padding: 2rem 1.5rem 1rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: var(--primary-gradient);
}

.app-logo {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.app-title {
    color: white;
    font-weight: 600;
    font-size: 1.125rem;
}

.app-content {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.book-card {
    display: flex;
    gap: 1rem;
    padding: 1rem;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 12px;
    transition: all var(--transition-base);
}

.book-card:hover {
    transform: translateX(5px);
    border-color: var(--accent-color);
}

.book-cover {
    width: 60px;
    height: 80px;
    border-radius: 6px;
    flex-shrink: 0;
}

.book-cover-1 {
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.book-cover-2 {
    background: linear-gradient(135deg, #f093fb, #f5576c);
}

.book-cover-3 {
    background: linear-gradient(135deg, #4facfe, #00f2fe);
}

.book-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.book-info h4 {
    font-size: 0.9375rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.book-info p {
    font-size: 0.75rem;
    color: var(--text-tertiary);
}

.progress-bar {
    width: 100%;
    height: 4px;
    background: var(--bg-tertiary);
    border-radius: 2px;
    overflow: hidden;
}

.progress {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: 2px;
}

.ai-suggestion {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 1rem;
    background: rgba(102, 126, 234, 0.1);
    border: 1px solid rgba(102, 126, 234, 0.3);
    border-radius: 12px;
    margin-top: 0.5rem;
}

.ai-icon {
    font-size: 1.5rem;
}

.ai-text {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.ai-label {
    font-size: 0.625rem;
    color: var(--accent-color);
    font-weight: 600;
    text-transform: uppercase;
}

.ai-title {
    font-size: 0.875rem;
    font-weight: 500;
}

/* ===== 品牌背书 ===== */
.brands {
    padding: 3rem 2rem;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.brands-container {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.brands-text {
    color: var(--text-tertiary);
    font-size: 0.875rem;
    margin-bottom: 2rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.brands-list {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 4rem;
    flex-wrap: wrap;
}

.brand-item {
    opacity: 0.6;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.brand-item:hover {
    opacity: 1;
    transform: translateY(-4px);
}

.brand-logo {
    width: 130px;
    height: 48px;
    background: linear-gradient(135deg, rgba(255,255,255,0.08) 0%, rgba(255,255,255,0.02) 100%);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.brand-logo::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(80, 168, 123, 0.2), transparent);
    transition: left 0.6s ease;
}

.brand-item:hover .brand-logo::before {
    left: 100%;
}

.brand-item:hover .brand-logo {
    border-color: rgba(80, 168, 123, 0.5);
    box-shadow: 0 8px 32px rgba(80, 168, 123, 0.2), 0 0 0 1px rgba(80, 168, 123, 0.1) inset;
    background: linear-gradient(135deg, rgba(80, 168, 123, 0.15) 0%, rgba(80, 168, 123, 0.05) 100%);
}

.brand-logo svg {
    width: 100%;
    height: 100%;
}

.brand-logo text {
    fill: var(--text-secondary);
    font-family: inherit;
    transition: fill 0.3s ease;
}

.brand-item:hover .brand-logo text {
    fill: #ffffff;
}

/* ===== 通用 Section ===== */
section {
    position: relative;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-tag {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.section-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.125rem;
    max-width: 600px;
    margin: 0 auto;
}

/* ===== 功能展示 ===== */
.features {
    padding: 6rem 0;
    background: var(--bg-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    align-items: start;
}

.feature-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 2rem;
    transition: all var(--transition-base);
}

.feature-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-color);
    box-shadow: var(--shadow-glow);
}

.feature-card.feature-large {
    grid-column: span 2;
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: 2rem;
    align-items: center;
}

.feature-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.feature-icon-large {
    width: 160px;
    height: 160px;
}

.feature-icon-wrapper {
    width: 64px;
    height: 64px;
    margin-bottom: 1.5rem;
    background: var(--primary-color);
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feature-icon-wrapper svg {
    width: 32px;
    height: 32px;
}

.feature-icon-wrapper svg path,
.feature-icon-wrapper svg circle,
.feature-icon-wrapper svg line {
    stroke: white !important;
}

.feature-icon-wrapper svg text {
    fill: white !important;
}

.feature-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(102, 126, 234, 0.2);
    color: var(--accent-color);
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
}

.feature-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.feature-description {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 1.5rem;
}

.feature-list {
    list-style: none;
}

.feature-list li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.feature-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--accent-color);
    font-weight: 600;
}

/* ===== 使用场景 ===== */
.scenarios {
    padding: 6rem 0;
    background: var(--bg-secondary);
}

.scenarios-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.scenarios-text {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.scenario-tabs {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.scenario-tab {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--glass-bg);
    border: 2px solid transparent;
    border-radius: 16px;
    cursor: pointer;
    transition: all var(--transition-base);
}

.scenario-tab:hover {
    border-color: rgba(102, 126, 234, 0.5);
}

.scenario-tab.active {
    border-color: var(--accent-color);
    background: rgba(102, 126, 234, 0.1);
}

.tab-icon {
    font-size: 2rem;
}

.tab-content h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.tab-content p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.scenarios-visual {
    position: relative;
    height: 500px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.scenario-card {
    position: absolute;
    width: 300px;
    height: 400px;
    border-radius: 20px;
    opacity: 0;
    transform: scale(0.9) translateY(20px);
    transition: all var(--transition-base);
    background: var(--bg-tertiary);
}

.scenario-card.active {
    opacity: 1;
    transform: scale(1) translateY(0);
}

.scenario-card-1 {
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.scenario-card-2 {
    background: linear-gradient(135deg, #f093fb, #f5576c);
}

.scenario-card-3 {
    background: linear-gradient(135deg, #4facfe, #00f2fe);
}

.scenario-card-4 {
    background: linear-gradient(135deg, #fa709a, #fee140);
}

/* ===== 用户评价 ===== */
.reviews {
    padding: 6rem 0;
    background: var(--bg-primary);
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
}

.review-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 20px;
    padding: 2rem;
    transition: all var(--transition-base);
}

.review-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-color);
    box-shadow: var(--shadow-glow);
}

.review-stars {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.review-text {
    color: var(--text-secondary);
    font-size: 1rem;
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.reviewer {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.reviewer-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary-gradient);
    flex-shrink: 0;
}

.reviewer-info h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.reviewer-info p {
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

/* ===== 下载区域 ===== */
.download {
    padding: 6rem 0;
    background: var(--bg-secondary);
    position: relative;
    overflow: hidden;
}

.download-bg {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80%;
    height: 80%;
    background: radial-gradient(circle, rgba(102, 126, 234, 0.15) 0%, transparent 70%);
    filter: blur(100px);
}

.download-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    position: relative;
    z-index: 1;
}

.download-left {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.download-title {
    font-size: clamp(2.5rem, 5vw, 3.5rem);
    font-weight: 800;
    line-height: 1.2;
}

.download-subtitle {
    color: var(--text-secondary);
    font-size: 1.125rem;
    line-height: 1.8;
}

.download-buttons {
    display: flex;
    gap: 1rem;
}

.qr-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    width: fit-content;
}

.qr-code {
    width: 150px;
    height: 150px;
    background: white;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.qr-code img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 6px;
}

.qr-section p {
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.download-right {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

.phones-showcase {
    position: relative;
    width: 100%;
    height: 500px;
}

.phone {
    position: absolute;
}

.phone-1 {
    left: 20%;
    top: 10%;
    animation: float 6s infinite ease-in-out 0s;
}

.phone-2 {
    right: 20%;
    bottom: 10%;
    animation: float 6s infinite ease-in-out 3s;
}

.phone-frame-mini {
    width: 200px;
    height: 400px;
    background: linear-gradient(145deg, #2a2a3a, #1a1a24);
    border-radius: 30px;
    padding: 8px;
    box-shadow: var(--shadow-lg);
}

.phone-notch-mini {
    position: absolute;
    top: 15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 20px;
    background: #000;
    border-radius: 15px;
    z-index: 10;
}

.phone-screen-mini {
    width: 100%;
    height: 100%;
    background: var(--bg-secondary);
    border-radius: 24px;
    overflow: hidden;
}

.app-header-mini {
    padding: 2rem 1rem 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--primary-gradient);
}

.app-logo-mini {
    width: 30px;
    height: 30px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
}

.app-title-mini {
    color: white;
    font-weight: 600;
    font-size: 0.875rem;
}

.reading-view {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    background: #ffffff;
    border-radius: 20px;
}

.app-screenshot-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 20px;
}

.qr-code-img {
    width: 100px;
    height: 100px;
    object-fit: contain;
    border-radius: 8px;
}

.book-cover-large {
    width: 120px;
    height: 160px;
    border-radius: 8px;
    background: linear-gradient(135deg, #667eea, #764ba2);
}

/* ===== FAQ ===== */
.faq {
    padding: 6rem 0;
    background: var(--bg-primary);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    margin-bottom: 1rem;
    overflow: hidden;
    transition: all var(--transition-base);
}

.faq-item:hover {
    border-color: var(--accent-color);
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    cursor: pointer;
}

.faq-question h4 {
    font-size: 1.125rem;
    font-weight: 600;
}

.faq-icon {
    width: 24px;
    height: 24px;
    transition: transform var(--transition-base);
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-base);
}

.faq-item.active .faq-answer {
    max-height: 300px;
}

.faq-answer p {
    padding: 0 2rem 1.5rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ===== Footer ===== */
.footer {
    padding: 4rem 0 2rem;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-bottom: 3rem;
}

.footer-brand .logo {
    margin-bottom: 1rem;
}

.footer-brand p {
    color: var(--text-tertiary);
    font-size: 0.9375rem;
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.social-link {
    width: 40px;
    height: 40px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.social-link:hover {
    background: var(--primary-gradient);
    border-color: transparent;
    color: white;
    transform: translateY(-3px);
}

.social-link svg {
    width: 20px;
    height: 20px;
}

.footer-links {
    display: flex;
    justify-content: flex-end;
    padding-right: 1rem;
    align-items: flex-start;
    gap: 2rem;
}

.footer-qrcode {
    text-align: center;
}

.footer-qrcode .qrcode-img {
    width: 100px;
    height: 100px;
    background: #fff;
    border-radius: 8px;
    padding: 8px;
    margin-bottom: 0.5rem;
}

.footer-qrcode .qrcode-img img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.footer-qrcode p {
    font-size: 0.8125rem;
    color: var(--text-tertiary);
    margin: 0;
}

.footer-column h4 {
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: 0.75rem;
}

.footer-column a {
    color: var(--text-tertiary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer-column a:hover {
    color: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--glass-border);
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

.footer-bottom a {
    color: var(--text-tertiary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.footer-bottom a:hover {
    color: var(--accent-color);
}

/* ===== 响应式设计 ===== */
@media (max-width: 1200px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .feature-card.feature-large {
        grid-column: span 2;
    }
    
    .reviews-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 992px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-left {
        align-items: center;
    }
    
    .hero-buttons {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .phone-mockup {
        margin-top: 2rem;
    }
    
    .scenarios-content {
        grid-template-columns: 1fr;
    }
    
    .download-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .download-left {
        align-items: center;
    }
    
    .download-buttons {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .footer-links {
        justify-content: flex-end;
        gap: 1.5rem;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(10, 10, 15, 0.98);
        backdrop-filter: blur(20px);
        padding: 2rem;
        flex-direction: column;
        gap: 1.5rem;
        border-bottom: 1px solid var(--border-color);
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .nav-cta {
        display: none;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .feature-card.feature-large {
        grid-template-columns: 1fr;
        grid-column: span 1;
    }
    
    .brands-list {
        gap: 2rem;
    }
    
    .footer-links {
        flex-direction: column;
        align-items: center;
        gap: 1.5rem;
    }
    
    .scenario-tabs {
        gap: 0.75rem;
    }
    
    .scenario-tab {
        padding: 1rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1.5rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn-large {
        width: 100%;
        min-width: auto;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 1.5rem;
        align-items: center;
    }
}

/* ===== 动画类 ===== */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease-out;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===== 自定义滚动条 ===== */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-color);
}