/* 
 * DDC Website Stylesheet
 * Modern Medical Aesthetic
 */

:root {
    --primary: hsl(210, 85%, 32%);
    --primary-dark: hsl(210, 85%, 22%);
    --primary-light: hsl(210, 75%, 52%);
    --accent: hsl(186, 70%, 45%);
    --surface: #ffffff;
    --background: #f8fafc;
    --text: hsl(215, 25%, 18%);
    --text-muted: hsl(215, 15%, 50%);
    --white: #ffffff;
    --border: hsl(214, 32%, 91%);
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 12px;
    --header-height: 80px;
}

[data-reveal] {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-reveal].revealed {
    opacity: 1;
    transform: translateY(0);
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    color: var(--text);
    background-color: var(--background);
    line-height: 1.6;
    overflow-x: hidden;
}

/* For Traditional Chinese characters */
[lang="zh"] body {
    font-family: 'Inter', 'Noto Sans TC', sans-serif;
}

h1, h2, h3, h4 {
    color: var(--primary);
    line-height: 1.2;
}

a {
    transition: all 0.2s ease;
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: var(--white);
    box-shadow: 0 4px 14px 0 rgba(10, 45, 94, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(10, 45, 94, 0.4);
}

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

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

/* Navigation */
header {
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
}

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

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

#site-logo {
    height: 52px;
    width: auto;
    display: block;
}

@media (max-width: 640px) {
    #site-logo {
        height: 36px;
    }
}

.nav-links {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-links a {
    font-weight: 500;
    font-size: 0.95rem;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--primary-light);
}

.lang-switcher {
    display: flex;
    gap: 10px;
    background: #f1f5f9;
    padding: 4px;
    border-radius: 30px;
}

.lang-btn {
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.lang-btn.active {
    background: var(--white);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    color: var(--primary);
}

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

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

.section-title {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

/* Hero Section */
.hero {
    padding: 180px 0 100px;
    position: relative;
    overflow: hidden;
    background: radial-gradient(circle at top right, rgba(24, 176, 200, 0.05) 0%, transparent 50%),
                radial-gradient(circle at bottom left, rgba(10, 45, 94, 0.05) 0%, transparent 50%);
}

.hero-content {
    max-width: 700px;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 25px;
    font-weight: 800;
    letter-spacing: -1.5px;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 40px;
}

/* Grids */
.grid {
    display: grid;
    gap: 30px;
}

.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

/* Service Card */
.card {
    background: var(--surface);
    border-radius: var(--radius);
    padding: 40px;
    border: 1px solid var(--border);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow);
    border-color: var(--primary-light);
}

.card-icon {
    width: 60px;
    height: 60px;
    background: rgba(10, 45, 94, 0.05);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    margin-bottom: 25px;
}

.card h3 {
    margin-bottom: 15px;
    font-size: 1.4rem;
}

/* Footer */
footer {
    background: #0f172a;
    color: rgba(255,255,255,0.7);
    padding: 80px 0 40px;
}

footer h4 {
    color: var(--white);
    margin-bottom: 25px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 60px;
}

.footer-bottom {
    padding-top: 40px;
    border-top: 1px solid rgba(255,255,255,0.1);
    text-align: center;
    font-size: 0.9rem;
}

/* Tabs for Pricing */
.tabs {
    display: flex;
    gap: 15px;
    margin-bottom: 40px;
    border-bottom: 1px solid var(--border);
    padding-bottom: 15px;
    overflow-x: auto;
}

.tab-btn {
    padding: 10px 20px;
    border-radius: 30px;
    font-weight: 600;
    cursor: pointer;
    background: transparent;
    border: 1px solid transparent;
    transition: all 0.3s ease;
    white-space: nowrap;
}

.tab-btn.active {
    background: var(--primary);
    color: var(--white);
}

.tab-btn:hover:not(.active) {
    background: rgba(10, 45, 94, 0.05);
}

.tab-content {
    display: none;
    animation: fadeIn 0.4s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Pricing Table */
.pricing-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.pricing-table th {
    background: var(--primary);
    color: var(--white);
    text-align: left;
    padding: 15px 20px;
    font-weight: 600;
}

.pricing-table td {
    padding: 15px 20px;
    border-bottom: 1px solid var(--border);
}

.pricing-table tr:last-child td {
    border-bottom: none;
}

.pricing-table tr:hover td {
    background-color: rgba(186, 190, 245, 0.1);
}

.price-val {
    font-weight: 700;
    color: var(--primary);
}

/* Page Headers */
.page-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    padding: 120px 0 60px;
    color: var(--white);
    text-align: center;
}

.page-header h1 {
    color: var(--white);
    font-size: 3rem;
    margin-bottom: 10px;
}

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

.reveal {
    animation: slideUp 0.8s ease forwards;
}