/* ========================================
   面个offer Landing Page - Bilibili Style
   Simple, Clean, Modern
   ======================================== */

/* ========================================
   CSS Variables - Bilibili Inspired Colors
   ======================================== */
:root {
    /* Primary Colors */
    --primary: #00AEEC;
    --primary-light: #23C9FF;
    --primary-dark: #0091CC;
    --secondary: #FB7299;
    --secondary-light: #FF8FAE;

    /* Accent background */
    --accent-bg: rgba(0, 174, 236, 0.08);

    /* Background */
    --bg-primary: #FFFFFF;
    --bg-secondary: #F4F5F7;
    --bg-tertiary: #E3E5E7;

    /* Text */
    --text-primary: #18191C;
    --text-secondary: #61666D;
    --text-tertiary: #9499A0;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-primary: 0 4px 20px rgba(0, 174, 236, 0.25);

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
    --transition-slow: 0.4s ease;
}

/* ========================================
   Reset & Base Styles
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

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

/* ========================================
   Typography
   ======================================== */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--text-primary);
}

h1 {
    font-size: clamp(2.25rem, 5vw, 3.5rem);
}

h2 {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
}

h3 {
    font-size: clamp(1.25rem, 3vw, 1.5rem);
}

p {
    font-size: 1rem;
    color: var(--text-secondary);
}

.text-highlight {
    color: var(--primary);
}

/* ========================================
   Layout
   ======================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

section {
    padding: 5rem 0;
}

/* ========================================
   Navigation
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 1rem 0;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    transition: var(--transition-normal);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

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

.brand-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9375rem;
    font-weight: 500;
    transition: var(--transition-fast);
}

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

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    text-decoration: none;
    transition: var(--transition-normal);
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(0, 174, 236, 0.35);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: var(--bg-primary);
    padding-top: 5rem;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 60%;
    height: 100%;
    background: var(--accent-bg);
    border-radius: 50%;
    filter: blur(80px);
    pointer-events: none;
}

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

.hero-content {
    position: relative;
    z-index: 2;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--accent-bg);
    border-radius: 100px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--primary);
    margin-bottom: 1.5rem;
}

.hero-badge::before {
    content: '';
    width: 8px;
    height: 8px;
    background: var(--primary);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {

    0%,
    100% {
        opacity: 1;
        transform: scale(1);
    }

    50% {
        opacity: 0.6;
        transform: scale(1.2);
    }
}

.hero-title {
    margin-bottom: 1.5rem;
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero-stats {
    display: flex;
    gap: 2.5rem;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--bg-tertiary);
}

.stat-item {
    text-align: left;
}

.stat-value {
    display: block;
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

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

/* Hero Visual */
.hero-visual {
    position: relative;
    z-index: 1;
}

.iphone-mockup {
    background: #1a1a1a;
    border-radius: 48px;
    box-shadow:
        0 25px 50px -12px rgba(0, 0, 0, 0.35),
        inset 0 0 0 3px #2d2d2d;
    padding: 12px;
    max-width: 300px;
    margin: 0 auto;
    position: relative;
}

.iphone-notch {
    position: absolute;
    top: 12px;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 28px;
    background: #1a1a1a;
    border-radius: 0 0 18px 18px;
    z-index: 10;
}

.iphone-screen {
    background: #0F1115;
    border-radius: 40px;
    overflow: hidden;
}

.screen-image {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 40px;
}

.screen-header {
    text-align: center;
    margin-bottom: 1.5rem;
}

.screen-title {
    color: white;
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.screen-subtitle {
    color: #00D26A;
    font-size: 0.8125rem;
}

.chat-container {
    display: flex;
    flex-direction: column;
    gap: 0.875rem;
}

.chat-bubble {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    max-width: 92%;
    opacity: 0;
    transform: translateY(10px);
}

.chat-bubble.ai {
    align-self: flex-start;
}

.chat-bubble.user {
    align-self: flex-end;
    flex-direction: row-reverse;
}

.bubble-avatar {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: #00D26A;
    color: white;
    font-size: 0.625rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.bubble-content {
    padding: 0.75rem 1rem;
    border-radius: 16px;
    font-size: 0.8125rem;
    line-height: 1.5;
    color: white;
}

.chat-bubble.ai .bubble-content {
    background: rgba(255, 255, 255, 0.1);
    border-bottom-left-radius: 4px;
}

.chat-bubble.user .bubble-content {
    background: #00D26A;
    border-bottom-right-radius: 4px;
}

/* Typing indicator */
.typing-indicator {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.75rem 1rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    width: fit-content;
    margin-left: 36px;
    opacity: 0;
}

.typing-indicator span {
    width: 6px;
    height: 6px;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    animation: typing 1.4s infinite ease-in-out;
}

.typing-indicator span:nth-child(1) {
    animation-delay: 0s;
}

.typing-indicator span:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-indicator span:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typing {

    0%,
    60%,
    100% {
        transform: translateY(0);
        opacity: 0.5;
    }

    30% {
        transform: translateY(-4px);
        opacity: 1;
    }
}

/* Chat bubble animations */
.animate-bubble {
    animation: bubbleIn 0.5s ease forwards;
}

.animate-bubble.delay-1 {
    animation-delay: 0.3s;
}

.animate-bubble.delay-2 {
    animation-delay: 1s;
}

.animate-bubble.delay-3 {
    animation-delay: 1.8s;
}

.animate-bubble.delay-4 {
    animation-delay: 2.6s;
}

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



/* ========================================
   Features Section
   ======================================== */
.features {
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 4rem;
}

.section-header h2 {
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.125rem;
}

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

.feature-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    transition: var(--transition-normal);
    border: 1px solid transparent;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary);
}

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
    font-size: 1.5rem;
}

.feature-icon.icon-blue {
    background: rgba(0, 174, 236, 0.1);
    color: var(--primary);
}

.feature-icon.icon-pink {
    background: rgba(251, 114, 153, 0.1);
    color: var(--secondary);
}

.feature-icon.icon-purple {
    background: rgba(147, 112, 219, 0.1);
    color: #9370DB;
}

.feature-icon.icon-green {
    background: rgba(0, 208, 132, 0.1);
    color: #00D084;
}

.feature-card h3 {
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
}

.feature-card p {
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* Feature Showcase - Gallery Style */
.feature-showcase {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 3rem;
    align-items: center;
    padding: 3rem 0;
    border-bottom: 1px solid var(--bg-tertiary);
}

.feature-showcase:last-child {
    border-bottom: none;
}

.feature-showcase.reverse {
    grid-template-columns: 2fr 1fr;
}

.feature-showcase.reverse .feature-info {
    order: 2;
}

.feature-showcase.reverse .feature-phones {
    order: 1;
}

.feature-info {
    padding: 1rem 0;
}

.feature-title {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.feature-desc {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.feature-phones {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.75rem;
}

.feature-phones.single {
    grid-template-columns: 1fr;
    justify-items: center;
}

.phone-item {
    background: #1a1a1a;
    border-radius: 20px;
    padding: 4px;
    box-shadow: var(--shadow-md);
    transition: var(--transition-normal);
}

.phone-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.phone-item img {
    width: 100%;
    height: auto;
    border-radius: 18px;
    display: block;
}

.phone-item.large {
    max-width: 180px;
}

/* ========================================
   CTA Section
   ======================================== */
.cta-section {
    background: var(--bg-primary);
    text-align: center;
}

.cta-card {
    background: var(--accent-bg);
    border-radius: var(--radius-xl);
    padding: 4rem 2rem;
    position: relative;
    overflow: hidden;
}

.cta-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(0, 174, 236, 0.05) 0%, transparent 50%);
    animation: rotate 20s linear infinite;
}

@keyframes rotate {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

.cta-content {
    position: relative;
    z-index: 1;
}

.cta-title {
    margin-bottom: 1rem;
}

.cta-desc {
    font-size: 1.125rem;
    margin-bottom: 2.5rem;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.qr-container {
    display: inline-block;
    background: white;
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.qr-box {
    width: 200px;
    height: 200px;
    background: white;
    border-radius: var(--radius-md);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    margin-bottom: 1rem;
}

.qr-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

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

.qr-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* ========================================
   Footer
   ======================================== */
.footer {
    background: var(--bg-secondary);
    padding: 2rem 0;
}

.footer-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    gap: 0.5rem;
}

.footer-brand {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
}

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

/* ========================================
   Animations
   ======================================== */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeIn 0.6s ease forwards;
}

.fade-in-delay-1 {
    animation-delay: 0.1s;
}

.fade-in-delay-2 {
    animation-delay: 0.2s;
}

.fade-in-delay-3 {
    animation-delay: 0.3s;
}

.fade-in-delay-4 {
    animation-delay: 0.4s;
}

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

/* Scroll animations */
.scroll-animate {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 968px) {
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 3rem;
    }

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

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

    .hero-visual {
        order: -1;
    }

    .iphone-mockup {
        max-width: 260px;
    }

    .feature-showcase,
    .feature-showcase.reverse {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

    .feature-showcase.reverse .feature-info,
    .feature-showcase.reverse .feature-phones {
        order: unset;
    }

    .feature-phones {
        grid-template-columns: repeat(2, 1fr);
        max-width: 400px;
        margin: 0 auto;
    }

    .phone-item.large {
        max-width: 150px;
    }
}

@media (max-width: 640px) {
    section {
        padding: 3rem 0;
    }

    .nav-links {
        gap: 1rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 1.5rem;
        align-items: center;
    }

    .stat-item {
        text-align: center;
    }

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

    .cta-card {
        padding: 3rem 1.5rem;
    }

    .footer-container {
        flex-direction: column;
        text-align: center;
    }
}