/* ==========================================
   友研 Landing Page - Styles
   ========================================== */

/* CSS Variables */
:root {
    /* Primary Colors - Warm Orange from App */
    --primary: #F5A623;
    --primary-dark: #E8941A;
    --primary-light: #FFB94D;
    --primary-subtle: #FFF5E6;
    
    /* Neutrals */
    --white: #FFFFFF;
    --black: #1A1A1A;
    --gray-50: #FAFAFA;
    --gray-100: #F5F5F5;
    --gray-200: #EEEEEE;
    --gray-300: #E0E0E0;
    --gray-400: #BDBDBD;
    --gray-500: #9E9E9E;
    --gray-600: #757575;
    --gray-700: #616161;
    --gray-800: #424242;
    --gray-900: #212121;
    
    /* Text Colors */
    --text-primary: #1A1A1A;
    --text-secondary: #616161;
    --text-muted: #9E9E9E;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #F5A623 0%, #FF8C40 100%);
    --gradient-warm: linear-gradient(135deg, #FFF5E6 0%, #FFE4CC 100%);
    --gradient-hero: linear-gradient(180deg, #FFF9F0 0%, #FFFFFF 100%);
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-primary: 0 10px 30px -5px rgba(245, 166, 35, 0.4);
    
    /* Typography */
    --font-display: 'Noto Serif SC', Georgia, 'Times New Roman', serif;
    --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans SC', sans-serif;
    
    /* Spacing */
    --section-padding: 120px;
    --container-max: 1200px;
    --container-padding: 24px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 300ms ease;
    --transition-slow: 500ms ease;
    
    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 32px;
    --radius-full: 9999px;
}

/* ==========================================
   Base Styles
   ========================================== */

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--white);
    overflow-x: hidden;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ==========================================
   Utility Classes
   ========================================== */

.section-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

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

/* ==========================================
   Navigation
   ========================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    transition: all var(--transition-base);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--container-padding);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
}

.logo-icon {
    width: 40px;
    height: 40px;
    object-fit: contain;
    display: block;
}

.logo-text {
    font-family: var(--font-display);
    font-size: 22px;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 40px;
}

.nav-links a {
    font-size: 15px;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
    position: relative;
}

.nav-links a:not(.nav-cta)::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width var(--transition-base);
}

.nav-links a:not(.nav-cta):hover {
    color: var(--text-primary);
}

.nav-links a:not(.nav-cta):hover::after {
    width: 100%;
}

.nav-cta {
    padding: 10px 24px;
    background: var(--gradient-primary);
    color: var(--white) !important;
    border-radius: var(--radius-full);
    font-weight: 500;
    box-shadow: var(--shadow-primary);
    transition: all var(--transition-base);
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 14px 35px -5px rgba(245, 166, 35, 0.5);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.mobile-menu-btn span {
    width: 24px;
    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: 120px 0 80px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-gradient {
    position: absolute;
    inset: 0;
    background: var(--gradient-hero);
}

.hero-pattern {
    position: absolute;
    inset: 0;
    opacity: 0.5;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(245, 166, 35, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(245, 166, 35, 0.05) 0%, transparent 50%);
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--container-padding);
    text-align: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--primary-subtle);
    border-radius: var(--radius-full);
    font-size: 14px;
    color: var(--primary-dark);
    font-weight: 500;
    margin-bottom: 24px;
    animation: fadeInUp 0.8s ease forwards;
}

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

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(36px, 5vw, 56px);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    animation: fadeInUp 0.8s ease 0.1s forwards;
    opacity: 0;
}

.title-line {
    display: block;
}

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

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 40px;
    animation: fadeInUp 0.8s ease 0.2s forwards;
    opacity: 0;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 60px;
    animation: fadeInUp 0.8s ease 0.3s forwards;
    opacity: 0;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    font-size: 16px;
    font-weight: 500;
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

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

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 16px 40px -5px rgba(245, 166, 35, 0.5);
}

.btn-secondary {
    background: var(--white);
    color: var(--text-primary);
    border: 1px solid var(--gray-200);
    box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-subtle);
}

.hero-stats {
    display: flex;
    align-items: center;
    gap: 32px;
    animation: fadeInUp 0.8s ease 0.4s forwards;
    opacity: 0;
}

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

.stat-number {
    font-family: var(--font-display);
    font-size: 42px;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
}

.stat-suffix {
    font-family: var(--font-display);
    font-size: 32px;
    font-weight: 600;
    color: var(--primary);
}

.stat-label {
    display: block;
    font-size: 14px;
    color: var(--text-muted);
    margin-top: 8px;
}

.stat-divider {
    width: 1px;
    height: 50px;
    background: var(--gray-200);
}

/* Hero Visual - Removed */

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-size: 12px;
    animation: fadeIn 1s ease 1s forwards;
    opacity: 0;
}

.scroll-mouse {
    width: 24px;
    height: 40px;
    border: 2px solid var(--gray-300);
    border-radius: 12px;
    position: relative;
}

.scroll-wheel {
    width: 4px;
    height: 8px;
    background: var(--primary);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll-bounce 2s infinite;
}

/* ==========================================
   Section Common Styles
   ========================================== */

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 80px;
}

.section-tag {
    display: inline-block;
    padding: 8px 20px;
    background: var(--primary-subtle);
    color: var(--primary-dark);
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-full);
    margin-bottom: 20px;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(32px, 4vw, 48px);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
}

.section-desc {
    font-size: 18px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ==========================================
   Features Section
   ========================================== */

.features {
    padding: var(--section-padding) 0;
    background: var(--gray-50);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 36px;
    transition: all var(--transition-base);
    border: 1px solid var(--gray-100);
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
    border-color: transparent;
}

.feature-card-large {
    grid-column: span 1;
    grid-row: span 2;
    display: flex;
    flex-direction: column;
}

.feature-icon {
    width: 64px;
    height: 64px;
    background: var(--gradient-warm);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    margin-bottom: 24px;
}

.feature-title {
    font-family: var(--font-display);
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 12px;
}

.feature-desc {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

.feature-visual {
    margin-top: auto;
    padding-top: 24px;
    flex: 1;
    display: flex;
    align-items: flex-end;
}

.feature-img {
    width: 100%;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
}

/* ==========================================
   Showcase Section
   ========================================== */

.showcase {
    padding: var(--section-padding) 0;
    background: var(--white);
    overflow: hidden;
}

.showcase-slider {
    position: relative;
    margin: 0 -24px;
    padding: 20px 0 40px;
    overflow: hidden;
}

.showcase-track {
    display: flex;
    gap: 32px;
    padding: 0 calc(50% - 140px);
    transition: transform 0.5s ease;
}

.showcase-item {
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    transition: all var(--transition-base);
    opacity: 0.5;
    transform: scale(0.9);
}

.showcase-item.active {
    opacity: 1;
    transform: scale(1);
}

.showcase-phone {
    width: 260px;
    background: var(--black);
    border-radius: 36px;
    padding: 10px;
    box-shadow: var(--shadow-xl);
    transition: all var(--transition-base);
}

.showcase-item.active .showcase-phone {
    box-shadow: 
        0 40px 80px -20px rgba(0, 0, 0, 0.2),
        0 20px 40px -20px rgba(245, 166, 35, 0.3);
}

.showcase-phone img {
    border-radius: 28px;
    background: var(--white);
}

.showcase-label {
    font-size: 15px;
    color: var(--text-secondary);
    font-weight: 500;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.showcase-item.active .showcase-label {
    opacity: 1;
    color: var(--primary-dark);
}

.showcase-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 24px;
    margin-top: 40px;
}

.showcase-btn {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--white);
    border: 1px solid var(--gray-200);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

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

.showcase-dots {
    display: flex;
    gap: 8px;
}

.showcase-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--gray-300);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.showcase-dot.active {
    width: 24px;
    border-radius: 4px;
    background: var(--primary);
}

/* ==========================================
   About Section
   ========================================== */

.about {
    padding: var(--section-padding) 0;
    background: var(--gray-50);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.about-content .section-tag {
    margin-bottom: 16px;
}

.about-content .section-title {
    text-align: left;
    margin-bottom: 24px;
}

.about-text {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 20px;
}

.about-highlights {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-top: 32px;
}

.highlight-item {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 15px;
    font-weight: 500;
}

.highlight-icon {
    width: 32px;
    height: 32px;
    background: var(--primary-subtle);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
}

.highlight-icon svg {
    width: 18px;
    height: 18px;
}

.about-visual {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.about-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: all var(--transition-base);
    border: 1px solid var(--gray-100);
}

.about-card:hover {
    transform: translateX(8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-subtle);
}

.about-card-icon {
    width: 72px;
    height: 72px;
    background: var(--gradient-warm);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    margin-bottom: 20px;
}

.about-card h4 {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
}

.about-card p {
    font-size: 15px;
    color: var(--text-secondary);
}

/* ==========================================
   CTA Section
   ========================================== */

.cta {
    position: relative;
    padding: 100px 0;
    overflow: hidden;
}

.cta-bg {
    position: absolute;
    inset: 0;
}

.cta-gradient {
    position: absolute;
    inset: 0;
    background: var(--gradient-primary);
}

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

.cta-title {
    font-family: var(--font-display);
    font-size: clamp(28px, 4vw, 40px);
    font-weight: 700;
    color: var(--white);
    margin-bottom: 16px;
}

.cta-desc {
    font-size: 18px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 40px;
}

.cta-actions {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

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

.btn-light:hover {
    transform: translateY(-3px);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.15);
}

.btn-outline-light {
    background: transparent;
    color: var(--white);
    border: 2px solid rgba(255, 255, 255, 0.5);
}

.btn-outline-light:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--white);
}

/* ==========================================
   Footer
   ========================================== */

.footer {
    background: var(--gray-900);
    color: var(--white);
    padding: 80px 0 40px;
}

.footer-main {
    display: flex;
    justify-content: space-between;
    padding-bottom: 60px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand .logo {
    margin-bottom: 16px;
}

.footer-brand .logo-icon {
    filter: brightness(0) invert(1);
}

.footer-brand .logo-text {
    color: var(--white);
}

.footer-tagline {
    font-size: 14px;
    color: var(--gray-400);
}

.footer-links {
    display: flex;
    gap: 80px;
}

.footer-group h5 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 20px;
    color: var(--gray-300);
}

.footer-group a {
    display: block;
    font-size: 14px;
    color: var(--gray-400);
    margin-bottom: 12px;
    transition: color var(--transition-fast);
}

.footer-group a:hover {
    color: var(--white);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 40px;
    font-size: 14px;
    color: var(--gray-500);
}

.footer-note {
    font-style: italic;
}

/* ==========================================
   Animations
   ========================================== */

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

@keyframes scroll-bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); opacity: 1; }
    50% { transform: translateX(-50%) translateY(10px); opacity: 0.5; }
}

/* Scroll Reveal */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.8s ease;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* ==========================================
   Responsive Design
   ========================================== */

@media (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }
    
    .hero-content {
        text-align: center;
    }
    
    .hero-actions {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .feature-card-large {
        grid-column: span 2;
        grid-row: span 1;
    }
    
    .about-grid {
        grid-template-columns: 1fr;
        gap: 60px;
    }
    
    .about-content .section-title {
        text-align: center;
    }
    
    .about-content {
        text-align: center;
    }
    
    .about-highlights {
        align-items: center;
    }
    
    .about-visual {
        flex-direction: row;
    }
    
    .about-card {
        flex: 1;
    }
    
    .footer-main {
        flex-direction: column;
        gap: 40px;
    }
    
    .footer-links {
        gap: 40px;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 60px;
    }
    
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .hero {
        padding-top: 100px;
    }
    
    .hero-subtitle br {
        display: none;
    }
    
    .hero-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }
    
    .stat-divider {
        width: 50px;
        height: 1px;
    }
    
    .phone-frame {
        width: 240px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .feature-card-large {
        grid-column: span 1;
    }
    
    .showcase-track {
        padding: 0 calc(50% - 120px);
    }
    
    .showcase-phone {
        width: 220px;
    }
    
    .about-visual {
        flex-direction: column;
    }
    
    .cta-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .footer-links {
        flex-wrap: wrap;
        gap: 32px;
    }
    
    .footer-group {
        min-width: 140px;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 8px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .section-header {
        margin-bottom: 48px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .feature-card {
        padding: 28px;
    }
    
    .showcase-phone {
        width: 200px;
        border-radius: 28px;
        padding: 8px;
    }
    
    .showcase-phone img {
        border-radius: 22px;
    }
}