/* ============================================================
   common.css - 公共基础样式
   Template: Modern v2.0
   ============================================================ */

/* ---------- CSS Variables ---------- */
:root {
    --color-primary: #6366f1;
    --color-primary-light: #818cf8;
    --color-primary-dark: #4f46e5;
    --color-accent: #f59e0b;
    --color-success: #10b981;
    --color-danger: #ef4444;
    --color-warning: #f59e0b;
    --color-info: #3b82f6;

    --color-bg: #ffffff;
    --color-bg-alt: #f8fafc;
    --color-bg-dark: #0f172a;
    --color-text: #1e293b;
    --color-text-secondary: #64748b;
    --color-text-muted: #94a3b8;
    --color-border: #e2e8f0;
    --color-border-light: #f1f5f9;

    --gradient-primary: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);
    --gradient-hero: linear-gradient(135deg, #0f172a 0%, #1e1b4b 50%, #312e81 100%);
    --gradient-card: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);

    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.1), 0 4px 10px rgba(0,0,0,0.06);
    --shadow-xl: 0 20px 50px rgba(0,0,0,0.15);

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', 'Monaco', monospace;
}

/* ---------- Reset & Base ---------- */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.7;
    color: var(--color-text);
    background: var(--color-bg);
    overflow-x: hidden;
}

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

a:hover {
    color: var(--color-primary-light);
}

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

ul, ol {
    list-style: none;
}

/* ---------- Container ---------- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 28px;
    font-size: 15px;
    font-weight: 600;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all var(--transition);
    white-space: nowrap;
    text-decoration: none;
    line-height: 1.5;
}

.btn-primary {
    background: var(--gradient-primary);
    color: #fff;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
    color: #fff;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.5);
}

.btn-outline {
    background: transparent;
    border: 2px solid rgba(255,255,255,0.3);
    color: #fff;
}

.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: rgba(255,255,255,0.5);
    color: #fff;
}

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

.btn-outline-white:hover {
    background: rgba(255,255,255,0.15);
    border-color: #fff;
    color: #fff;
}

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

.btn-white:hover {
    color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.btn-lg {
    padding: 16px 36px;
    font-size: 17px;
    border-radius: var(--radius-lg);
}

/* ---------- Section Common ---------- */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 18px;
    font-size: 13px;
    font-weight: 600;
    color: var(--color-primary);
    background: rgba(99, 102, 241, 0.1);
    border-radius: var(--radius-full);
    margin-bottom: 16px;
    letter-spacing: 0.5px;
}

.section-title {
    font-size: 40px;
    font-weight: 800;
    color: var(--color-text);
    margin-bottom: 16px;
    line-height: 1.3;
}

.section-desc {
    font-size: 18px;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ---------- Header / Navbar ---------- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: all var(--transition);
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: var(--shadow-md);
}

.header.scrolled .navbar {
    height: 64px;
}

.header.scrolled .navbar-brand {
    color: var(--color-text);
}

.header.scrolled .nav-link {
    color: var(--color-text-secondary);
}

.header.scrolled .nav-link:hover,
.header.scrolled .nav-link.active {
    color: var(--color-primary);
}

.header.scrolled .navbar-toggle span {
    background: var(--color-text);
}

.navbar {
    display: flex;
    align-items: center;
    height: 80px;
    transition: height var(--transition);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 22px;
    font-weight: 800;
    color: #fff;
    text-decoration: none;
}

.navbar-brand:hover {
    color: #fff;
}

.logo-icon {
    display: flex;
    align-items: center;
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    padding: 8px 18px;
    font-size: 15px;
    font-weight: 500;
    color: rgba(255,255,255,0.7);
    border-radius: var(--radius-md);
    transition: all var(--transition);
    text-decoration: none;
}

.nav-link:hover,
.nav-link.active {
    color: #fff;
    background: rgba(255,255,255,0.1);
}

.nav-link-btn {
    background: rgba(255,255,255,0.2);
    color: #fff;
    padding: 10px 22px;
    margin-left: 8px;
    font-weight: 600;
}

.nav-link-btn:hover {
    background: rgba(255,255,255,0.3);
    color: #fff;
}

/* Mobile Toggle */
.navbar-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 1001;
}

.navbar-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: #fff;
    border-radius: 2px;
    transition: all var(--transition);
}

.navbar-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.navbar-toggle.active span:nth-child(2) {
    opacity: 0;
}

.navbar-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ---------- Footer ---------- */
.footer {
    background: var(--color-bg-dark);
    color: rgba(255,255,255,0.7);
}

.footer-top {
    padding: 70px 0 40px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
}

.footer-title {
    font-size: 18px;
    font-weight: 700;
    color: #fff;
    margin-bottom: 20px;
}

.footer-desc {
    font-size: 14px;
    line-height: 1.8;
    margin-bottom: 20px;
}

.footer-social {
    display: flex;
    gap: 12px;
}

.social-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.7);
    transition: all var(--transition);
}

.social-link:hover {
    background: var(--color-primary);
    color: #fff;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a,
.footer-links li {
    color: rgba(255,255,255,0.6);
    font-size: 14px;
    transition: color var(--transition);
}

.footer-links a:hover {
    color: #fff;
}

.footer-contact p {
    font-size: 14px;
    margin-bottom: 10px;
}

.footer-contact a {
    color: rgba(255,255,255,0.8);
}

.footer-contact a:hover {
    color: var(--color-primary-light);
}

.footer-bottom {
    padding: 24px 0;
    border-top: 1px solid rgba(255,255,255,0.08);
    text-align: center;
    font-size: 13px;
    color: rgba(255,255,255,0.4);
}

/* ---------- Responsive ---------- */
@media (max-width: 992px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }

    .section-title {
        font-size: 30px;
    }

    .section-desc {
        font-size: 16px;
    }

    .navbar-toggle {
        display: flex;
    }

    .navbar-nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--color-bg-dark);
        flex-direction: column;
        padding: 100px 30px 30px;
        gap: 4px;
        transition: right var(--transition-slow);
        z-index: 1000;
    }

    .navbar-nav.active {
        right: 0;
    }

    .nav-link {
        width: 100%;
        padding: 12px 18px;
        font-size: 16px;
    }

    .nav-link-btn {
        margin-left: 0;
        margin-top: 8px;
        text-align: center;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
}

@media (max-width: 480px) {
    .section-title {
        font-size: 26px;
    }
}

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

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes pulse {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 0.8; }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

[data-aos="fade-up"] {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-aos="fade-up"].aos-animate {
    opacity: 1;
    transform: translateY(0);
}