/* ==========================================
   CSS CUSTOM PROPERTIES (Design Tokens)
   ========================================== */
:root {
    /* Colors */
    --primary-color: #FF6347;
    --secondary-color: #FFD700;
    --accent-color: #32CD32;
    --dark-bg: #1a1a1a;
    --light-bg: #ffffff;
    --text-dark: #333333;
    --text-light: #ffffff;
    --text-gray: #666666;
    --border-color: #e0e0e0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-heading: 'Roboto', 'Arial Black', sans-serif;
    --font-body: 'Noto Sans SC', 'Roboto', sans-serif;
    
    /* Spacing */
    --corner-radius: 12px;
    --grid-spacing: 8px;
    --container-width: 1200px;
    
    /* Transitions */
    --transition: all 0.3s ease;
}

/* ==========================================
   GLOBAL RESET & BASE STYLES
   ========================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

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

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

ul {
    list-style: none;
}

/* ==========================================
   CONTAINER & LAYOUT
   ========================================== */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 calc(var(--grid-spacing) * 3);
}

section {
    padding: calc(var(--grid-spacing) * 10) 0;
}

/* ==========================================
   TOP NAVIGATION BAR
   ========================================== */
.top-nav {
    background: var(--light-bg);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: calc(var(--grid-spacing) * 2) calc(var(--grid-spacing) * 3);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: calc(var(--grid-spacing) * 1.5);
    font-weight: 900;
    font-size: 1.3rem;
    font-family: var(--font-heading);
    color: var(--primary-color);
}

.logo i {
    font-size: 2rem;
    animation: heartbeat 1.5s ease-in-out infinite;
}

@keyframes heartbeat {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.nav-menu {
    display: flex;
    gap: calc(var(--grid-spacing) * 4);
    align-items: center;
}

.nav-menu a {
    font-weight: 500;
    position: relative;
    padding: calc(var(--grid-spacing) * 1) 0;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: var(--primary-color);
    transition: var(--transition);
}

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

.btn-donate {
    background: var(--primary-color);
    color: var(--text-light) !important;
    padding: calc(var(--grid-spacing) * 1.5) calc(var(--grid-spacing) * 3);
    border-radius: var(--corner-radius);
    font-weight: 600;
}

.btn-donate:hover {
    background: #ff4025;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.lang-switch {
    background: var(--secondary-color);
    border: none;
    padding: calc(var(--grid-spacing) * 1) calc(var(--grid-spacing) * 2);
    border-radius: var(--corner-radius);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-body);
}

.lang-switch:hover {
    background: #ffd000;
    transform: scale(1.05);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    transition: var(--transition);
}

/* ==========================================
   HERO SECTION
   ========================================== */
.hero {
    position: relative;
    height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color) 0%, #ff8570 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><circle cx="50" cy="50" r="2" fill="white" opacity="0.1"/></svg>');
    background-size: 100px 100px;
    animation: moveBackground 20s linear infinite;
}

@keyframes moveBackground {
    0% { transform: translate(0, 0); }
    100% { transform: translate(100px, 100px); }
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.2);
}

.hero-content {
    position: relative;
    z-index: 100;
    text-align: center;
    color: #ffffff;
    max-width: 900px;
    padding: 0 calc(var(--grid-spacing) * 3);
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 900;
    font-family: var(--font-heading);
    margin-bottom: calc(var(--grid-spacing) * 3);
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.5rem);
    margin-bottom: calc(var(--grid-spacing) * 5);
    opacity: 1;
    animation: fadeInUp 1s ease 0.2s both;
    text-shadow: 
        0 2px 4px rgba(0, 0, 0, 0.9),
        0 4px 8px rgba(0, 0, 0, 0.7),
        0 8px 16px rgba(0, 0, 0, 0.5);
    font-weight: 500;
}

.hero-buttons {
    display: flex;
    gap: calc(var(--grid-spacing) * 3);
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 1s ease 0.4s both;
}

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

.hero-scroll {
    position: absolute;
    bottom: calc(var(--grid-spacing) * 5);
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
    color: var(--text-light);
    font-size: 2rem;
    opacity: 0.8;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

/* ==========================================
   BUTTONS
   ========================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: calc(var(--grid-spacing) * 1.5);
    padding: calc(var(--grid-spacing) * 2) calc(var(--grid-spacing) * 4);
    border-radius: var(--corner-radius);
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
    font-family: var(--font-body);
}

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

.btn-primary:hover {
    background: #ff4025;
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--secondary-color);
    color: var(--text-dark);
}

.btn-secondary:hover {
    background: #ffd000;
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-accent {
    background: var(--accent-color);
    color: var(--text-light);
}

.btn-accent:hover {
    background: #2eb82e;
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

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

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

.btn-small {
    padding: calc(var(--grid-spacing) * 1.5) calc(var(--grid-spacing) * 3);
    font-size: 0.9rem;
}

.btn-large {
    padding: calc(var(--grid-spacing) * 2.5) calc(var(--grid-spacing) * 5);
    font-size: 1.1rem;
}

/* ==========================================
   STATS SECTION
   ========================================== */
.stats-section {
    background: var(--light-bg);
    padding: calc(var(--grid-spacing) * 8) 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: calc(var(--grid-spacing) * 4);
}

.stat-card {
    text-align: center;
    padding: calc(var(--grid-spacing) * 4);
    background: linear-gradient(135deg, #fff 0%, #f8f8f8 100%);
    border-radius: var(--corner-radius);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.stat-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: calc(var(--grid-spacing) * 2);
}

.stat-number {
    font-size: 3rem;
    font-weight: 900;
    color: var(--primary-color);
    font-family: var(--font-heading);
}

.stat-label {
    color: var(--text-gray);
    font-weight: 500;
}

/* ==========================================
   SECTION HEADERS
   ========================================== */
.section-header {
    text-align: center;
    margin-bottom: calc(var(--grid-spacing) * 8);
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 900;
    font-family: var(--font-heading);
    color: var(--text-dark);
    margin-bottom: calc(var(--grid-spacing) * 2);
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--text-gray);
}

/* ==========================================
   ABOUT SECTION
   ========================================== */
.about-section {
    background: #f9f9f9;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: calc(var(--grid-spacing) * 8);
    align-items: center;
}

.about-text p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: calc(var(--grid-spacing) * 3);
    color: var(--text-gray);
}

.about-image {
    position: relative;
}

.image-placeholder {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    border-radius: var(--corner-radius);
    aspect-ratio: 1/1;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 8rem;
    box-shadow: var(--shadow-lg);
}

/* ==========================================
   PROGRAMS SECTION
   ========================================== */
.programs-section {
    background: var(--light-bg);
}

.programs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: calc(var(--grid-spacing) * 4);
}

.program-card {
    background: var(--light-bg);
    border: 2px solid var(--border-color);
    border-radius: var(--corner-radius);
    padding: calc(var(--grid-spacing) * 4);
    transition: var(--transition);
}

.program-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.program-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: calc(var(--grid-spacing) * 3);
    color: var(--text-light);
    font-size: 2.5rem;
}

.program-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: calc(var(--grid-spacing) * 2);
    font-family: var(--font-heading);
}

.program-description {
    color: var(--text-gray);
    margin-bottom: calc(var(--grid-spacing) * 3);
    line-height: 1.7;
}

.program-link {
    color: var(--primary-color);
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: calc(var(--grid-spacing) * 1);
}

.program-link:hover {
    gap: calc(var(--grid-spacing) * 2);
}

/* ==========================================
   EVENTS SECTION
   ========================================== */
.events-section {
    background: #f9f9f9;
}

.events-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: calc(var(--grid-spacing) * 4);
    margin-bottom: calc(var(--grid-spacing) * 6);
}

.event-card {
    background: var(--light-bg);
    border-radius: var(--corner-radius);
    box-shadow: var(--shadow);
    display: flex;
    overflow: hidden;
    transition: var(--transition);
}

.event-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.event-date {
    background: var(--primary-color);
    color: var(--text-light);
    padding: calc(var(--grid-spacing) * 3);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-width: 100px;
}

.date-day {
    font-size: 2.5rem;
    font-weight: 900;
    line-height: 1;
    font-family: var(--font-heading);
}

.date-month {
    font-size: 1rem;
    font-weight: 600;
    text-transform: uppercase;
}

.event-content {
    padding: calc(var(--grid-spacing) * 3);
    flex: 1;
}

.event-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: calc(var(--grid-spacing) * 2);
    font-family: var(--font-heading);
}

.event-description {
    color: var(--text-gray);
    margin-bottom: calc(var(--grid-spacing) * 2);
}

.event-meta {
    display: flex;
    flex-direction: column;
    gap: calc(var(--grid-spacing) * 1);
    color: var(--text-gray);
    font-size: 0.9rem;
    margin-bottom: calc(var(--grid-spacing) * 2);
}

.event-meta i {
    color: var(--primary-color);
    margin-right: calc(var(--grid-spacing) * 1);
}

.section-cta {
    text-align: center;
}

/* ==========================================
   CALL TO ACTION SECTION
   ========================================== */
.cta-section {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    color: var(--text-light);
    text-align: center;
}

.cta-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 900;
    font-family: var(--font-heading);
    margin-bottom: calc(var(--grid-spacing) * 3);
}

.cta-subtitle {
    font-size: 1.2rem;
    margin-bottom: calc(var(--grid-spacing) * 5);
    opacity: 0.95;
}

.cta-buttons {
    display: flex;
    gap: calc(var(--grid-spacing) * 3);
    justify-content: center;
    flex-wrap: wrap;
}

/* ==========================================
   FOOTER
   ========================================== */
.footer {
    background: var(--dark-bg);
    color: var(--text-light);
    padding: calc(var(--grid-spacing) * 8) 0 calc(var(--grid-spacing) * 4) 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: calc(var(--grid-spacing) * 6);
    margin-bottom: calc(var(--grid-spacing) * 6);
}

.footer-title {
    font-size: 1.5rem;
    font-weight: 900;
    margin-bottom: calc(var(--grid-spacing) * 2);
    font-family: var(--font-heading);
    color: var(--secondary-color);
}

.footer-text {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: calc(var(--grid-spacing) * 3);
}

.social-links {
    display: flex;
    gap: calc(var(--grid-spacing) * 2);
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-heading {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: calc(var(--grid-spacing) * 3);
    font-family: var(--font-heading);
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: calc(var(--grid-spacing) * 2);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--secondary-color);
    padding-left: calc(var(--grid-spacing) * 1);
}

.footer-contact {
    display: flex;
    flex-direction: column;
    gap: calc(var(--grid-spacing) * 2);
    color: rgba(255, 255, 255, 0.8);
}

.footer-contact i {
    color: var(--primary-color);
    margin-right: calc(var(--grid-spacing) * 1.5);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: calc(var(--grid-spacing) * 4);
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

/* ==========================================
   MOBILE BOTTOM NAVIGATION
   ========================================== */
.bottom-nav {
    display: none;
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--light-bg);
    box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.1);
    z-index: 999;
    padding: calc(var(--grid-spacing) * 1) 0;
}

.bottom-nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: calc(var(--grid-spacing) * 1);
    color: var(--text-gray);
    font-size: 0.75rem;
    transition: var(--transition);
}

.bottom-nav-item i {
    font-size: 1.5rem;
    margin-bottom: calc(var(--grid-spacing) * 0.5);
}

.bottom-nav-item.active,
.bottom-nav-item:hover {
    color: var(--primary-color);
}

/* ==========================================
   RESPONSIVE DESIGN
   ========================================== */
@media (max-width: 968px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--light-bg);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: calc(var(--grid-spacing) * 3) 0;
        gap: calc(var(--grid-spacing) * 2);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .programs-grid {
        grid-template-columns: 1fr;
    }
    
    .events-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    /* Show bottom navigation on mobile */
    .bottom-nav {
        display: flex;
    }
    
    /* Add padding to body to account for bottom nav */
    body {
        padding-bottom: 70px;
    }
}

@media (max-width: 600px) {
    .hero {
        height: 100vh;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .hero-buttons .btn {
        width: 100%;
        justify-content: center;
    }
    
    .event-card {
        flex-direction: column;
    }
    
    .event-date {
        flex-direction: row;
        gap: calc(var(--grid-spacing) * 2);
        padding: calc(var(--grid-spacing) * 2);
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: stretch;
    }
    
    .cta-buttons .btn {
        width: 100%;
    }
}

/* ==========================================
   UTILITY CLASSES
   ========================================== */
.text-center {
    text-align: center;
}

.mt-4 {
    margin-top: calc(var(--grid-spacing) * 4);
}

.mb-4 {
    margin-bottom: calc(var(--grid-spacing) * 4);
}

/* Language toggle - hide inactive language */
.zh {
    display: none !important;
}

body[data-lang="zh"] .en {
    display: none !important;
}

body[data-lang="zh"] .zh {
    display: inline !important;
}

/* Block-level elements in Chinese */
body[data-lang="zh"] p.zh,
body[data-lang="zh"] div.zh,
body[data-lang="zh"] h1.zh,
body[data-lang="zh"] h2.zh,
body[data-lang="zh"] h3.zh,
body[data-lang="zh"] h4.zh,
body[data-lang="zh"] h5.zh,
body[data-lang="zh"] h6.zh,
body[data-lang="zh"] li.zh,
body[data-lang="zh"] section.zh {
    display: block !important;
}

/* Span elements stay inline */
body[data-lang="zh"] span.zh {
    display: inline !important;
}