/* ===========================
   YC POWER AND OVERSEAS
   Company Website Styles
   =========================== */

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

:root {
    --primary: #0a1628;
    --primary-light: #132744;
    --accent: #00d4ff;
    --accent-hover: #00b8e6;
    --accent-glow: rgba(0, 212, 255, 0.3);
    --text: #e0e6ed;
    --text-light: #8899aa;
    --bg: #0a1628;
    --bg-alt: #0f1f3a;
    --card-bg: rgba(19, 39, 68, 0.6);
    --border: rgba(0, 212, 255, 0.15);
    --shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
    --radius: 12px;
    --transition: 0.3s ease;
    --gradient-1: linear-gradient(135deg, #0a1628 0%, #132744 50%, #1a3a5c 100%);
    --gradient-accent: linear-gradient(135deg, #00d4ff 0%, #0088ff 100%);
}

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

body {
    font-family: 'Noto Sans SC', 'Inter', -apple-system, sans-serif;
    color: var(--text);
    line-height: 1.7;
    background: var(--gradient-1);
    overflow-x: hidden;
    min-height: 100vh;
}

.en-mode body {
    font-family: 'Inter', -apple-system, sans-serif;
}

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

/* --- Navbar --- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 22, 40, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    transition: var(--transition);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

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

.logo-icon {
    font-size: 28px;
}

.logo-text {
    display: flex;
    flex-direction: column;
    line-height: 1.2;
}

.logo-zh {
    font-size: 16px;
    font-weight: 700;
    color: var(--accent);
    text-shadow: 0 0 10px var(--accent-glow);
}

.logo-en {
    font-size: 10px;
    font-weight: 500;
    color: var(--text-light);
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-link {
    text-decoration: none;
    color: var(--text);
    font-size: 14px;
    font-weight: 500;
    position: relative;
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--accent);
    text-shadow: 0 0 8px var(--accent-glow);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-accent);
    box-shadow: 0 0 8px var(--accent-glow);
    transition: var(--transition);
}

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

.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 8px 16px;
    border: 2px solid var(--accent);
    border-radius: 24px;
    background: transparent;
    color: var(--accent);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 0 10px var(--accent-glow);
}

.lang-btn:hover {
    background: var(--accent);
    color: var(--primary);
    box-shadow: 0 0 20px var(--accent-glow);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
}

/* --- Hero --- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: var(--gradient-1);
    color: #fff;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.1) 0%, transparent 70%);
    animation: float 8s ease-in-out infinite;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: -30%;
    left: -10%;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(0, 136, 255, 0.08) 0%, transparent 70%);
    animation: float 10s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-40px) rotate(5deg); }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    padding: 0 24px;
}

.hero-title {
    font-size: clamp(36px, 6vw, 64px);
    font-weight: 700;
    margin-bottom: 16px;
    letter-spacing: 2px;
}

.hero-title .en-text {
    display: none;
}

.en-mode .hero-title .zh-text {
    display: none;
}

.en-mode .hero-title .en-text {
    display: block;
    font-size: clamp(28px, 4vw, 48px);
}

.hero-subtitle {
    font-size: clamp(16px, 2.5vw, 22px);
    font-weight: 300;
    margin-bottom: 40px;
    opacity: 0.9;
}

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

.btn {
    display: inline-block;
    padding: 14px 36px;
    border-radius: 30px;
    font-size: 15px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

.btn-primary {
    background: var(--gradient-accent);
    color: var(--primary);
    border-color: var(--accent);
    font-weight: 700;
}

.btn-primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 30px var(--accent-glow);
}

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

.btn-outline:hover {
    background: rgba(255,255,255,0.1);
    border-color: #fff;
    transform: translateY(-2px);
}

.btn-full {
    width: 100%;
    text-align: center;
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 2;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    opacity: 0.7;
    animation: bounce 2s ease-in-out infinite;
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid #fff;
    border-bottom: 2px solid #fff;
    transform: rotate(45deg);
}

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

/* --- Sections --- */
.section {
    padding: 100px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 20px;
    background: rgba(0, 212, 255, 0.1);
    color: var(--accent);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 16px;
    border: 1px solid var(--border);
    text-shadow: 0 0 8px var(--accent-glow);
}

.section-title {
    font-size: clamp(28px, 4vw, 40px);
    color: var(--accent);
    margin-bottom: 16px;
    text-shadow: 0 0 10px var(--accent-glow);
}

.section-title .en-text {
    display: none;
}

.en-mode .section-title .zh-text {
    display: none;
}

.en-mode .section-title .en-text {
    display: inline;
}

.section-desc {
    font-size: 16px;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

/* --- About --- */
.about {
    background: var(--bg-alt);
    position: relative;
}

.about::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.about-card {
    background: var(--card-bg);
    padding: 40px 32px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: var(--transition);
    text-align: center;
    backdrop-filter: blur(10px);
}

.about-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0, 212, 255, 0.15);
    border-color: var(--accent);
}

.about-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.about-card h3 {
    font-size: 20px;
    color: var(--accent);
    margin-bottom: 12px;
    text-shadow: 0 0 8px var(--accent-glow);
}

.about-card p {
    color: var(--text-light);
    font-size: 14px;
    line-height: 1.8;
}

/* --- Services --- */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.service-card {
    background: var(--card-bg);
    padding: 40px 32px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-accent);
    transform: scaleX(0);
    transition: var(--transition);
    box-shadow: 0 0 10px var(--accent-glow);
}

.service-card:hover::before {
    transform: scaleX(1);
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0, 212, 255, 0.15);
    border-color: var(--accent);
}

.service-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.service-card h3 {
    font-size: 22px;
    color: var(--accent);
    margin-bottom: 12px;
    text-shadow: 0 0 8px var(--accent-glow);
}

.service-card p {
    color: var(--text-light);
    margin-bottom: 20px;
    font-size: 14px;
}

.service-list {
    list-style: none;
    padding: 0;
}

.service-list li {
    padding: 8px 0;
    padding-left: 20px;
    position: relative;
    color: var(--text-light);
    font-size: 14px;
}

.service-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: bold;
}

/* --- Advantages --- */
.advantages {
    background: var(--bg-alt);
    position: relative;
}

.advantages::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.adv-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 32px;
}

.adv-item {
    text-align: center;
    padding: 32px 24px;
    background: var(--card-bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.adv-number {
    font-size: 48px;
    font-weight: 700;
    color: var(--accent);
    margin-bottom: 16px;
    text-shadow: 0 0 15px var(--accent-glow);
}

.adv-item h3 {
    font-size: 20px;
    color: var(--accent);
    margin-bottom: 12px;
    text-shadow: 0 0 8px var(--accent-glow);
}

.adv-item p {
    color: var(--text-light);
    font-size: 14px;
}

/* --- Stats --- */
.stats {
    background: var(--gradient-1);
    color: #fff;
    padding: 80px 0;
    position: relative;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    text-align: center;
}

.stat-item {
    display: flex;
    align-items: baseline;
    justify-content: center;
    gap: 4px;
}

.stat-number {
    font-size: 56px;
    font-weight: 700;
    line-height: 1;
}

.stat-unit {
    font-size: 28px;
    font-weight: 300;
}

.stat-label {
    grid-column: 1 / -1;
    font-size: 14px;
    opacity: 0.8;
    margin-top: 8px;
}

/* --- Contact --- */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.contact-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}

.contact-icon {
    font-size: 28px;
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 16px;
    color: var(--accent);
    margin-bottom: 4px;
    text-shadow: 0 0 8px var(--accent-glow);
}

.contact-item p {
    color: var(--text-light);
    font-size: 14px;
}

.contact-form {
    background: var(--card-bg);
    padding: 40px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    backdrop-filter: blur(10px);
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 14px;
    font-family: inherit;
    transition: var(--transition);
    background: rgba(10, 22, 40, 0.8);
    color: var(--text);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-group textarea {
    resize: vertical;
}

/* --- Footer --- */
.footer {
    background: rgba(10, 22, 40, 0.95);
    color: rgba(255,255,255,0.8);
    padding: 60px 0 30px;
    border-top: 1px solid var(--border);
}

.footer-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 30px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    flex-wrap: wrap;
    gap: 20px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    color: #fff;
}

.footer-brand h3 {
    font-size: 18px;
    color: var(--accent);
    text-shadow: 0 0 8px var(--accent-glow);
}

.footer-brand p {
    font-size: 12px;
    opacity: 0.6;
}

.footer-links {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.footer-links a {
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    font-size: 14px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--accent);
    text-shadow: 0 0 8px var(--accent-glow);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    font-size: 13px;
    opacity: 0.6;
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(10, 22, 40, 0.95);
        flex-direction: column;
        padding: 20px;
        gap: 16px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow);
        backdrop-filter: blur(12px);
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-menu-btn {
        display: flex;
    }

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

    .hero-title {
        font-size: 32px;
    }

    .section {
        padding: 60px 0;
    }

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

/* --- Language Toggle --- */
.zh-text, .en-text {
    transition: opacity 0.3s ease;
}

/* --- Scroll Animations --- */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}