/* ============================================
   Hong Kong Mathematics Education Center
   Modern, Clean, and Responsive CSS
   ============================================ */

/* CSS Variables */
:root {
    --primary: #4F46E5;
    --primary-dark: #4338CA;
    --primary-light: #818CF8;
    --secondary: #10B981;
    --secondary-dark: #059669;
    --accent: #F59E0B;
    --accent-light: #FCD34D;
    --danger: #EF4444;
    --success: #22C55E;

    --text-primary: #1F2937;
    --text-secondary: #6B7280;
    --text-light: #9CA3AF;

    --bg-primary: #FFFFFF;
    --bg-secondary: #F9FAFB;
    --bg-tertiary: #F3F4F6;

    --border-color: #E5E7EB;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 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);

    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;

    --transition: all 0.3s ease;
    --font-family: 'Noto Sans TC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

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

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

ul {
    list-style: none;
}

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

button, input, select, textarea {
    font-family: inherit;
    font-size: inherit;
    border: none;
    outline: none;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ============================================
   Header & Navigation
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

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

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    border-radius: var(--radius);
    font-size: 1.5rem;
}

.logo-text {
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-link {
    padding: 0.5rem 1rem;
    color: var(--text-secondary);
    font-weight: 500;
    border-radius: var(--radius);
    transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
    color: var(--primary);
    background: rgba(79, 70, 229, 0.08);
}

.btn-contact {
    background: var(--primary);
    color: white !important;
    padding: 0.5rem 1.25rem !important;
}

.btn-contact:hover {
    background: var(--primary-dark);
    color: white !important;
}

/* Mobile Navigation Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 0.5rem;
    background: none;
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    width: 25px;
    height: 2px;
    background: var(--text-primary);
    transition: var(--transition);
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    overflow: hidden;
    padding-top: 70px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.math-symbols {
    position: absolute;
    inset: 0;
}

.math-symbols .symbol {
    position: absolute;
    font-size: 3rem;
    color: rgba(255, 255, 255, 0.1);
    animation: float 6s ease-in-out infinite;
}

.symbol:nth-child(1) { top: 10%; left: 10%; animation-delay: 0s; }
.symbol:nth-child(2) { top: 20%; right: 15%; animation-delay: 1s; }
.symbol:nth-child(3) { bottom: 30%; left: 20%; animation-delay: 2s; }
.symbol:nth-child(4) { top: 40%; left: 50%; animation-delay: 0.5s; }
.symbol:nth-child(5) { bottom: 20%; right: 25%; animation-delay: 1.5s; }
.symbol:nth-child(6) { top: 60%; left: 80%; animation-delay: 2.5s; }
.symbol:nth-child(7) { bottom: 40%; left: 5%; animation-delay: 3s; }
.symbol:nth-child(8) { top: 15%; left: 70%; animation-delay: 0.8s; }

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(10deg); }
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
    padding: 2rem 0;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-title .highlight {
    background: linear-gradient(90deg, #FCD34D, #F59E0B);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    opacity: 0.9;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
}

.stat-label {
    display: block;
    font-size: 0.875rem;
    opacity: 0.8;
    margin-top: 0.25rem;
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero-wave {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    line-height: 0;
}

.hero-wave svg {
    width: 100%;
    height: 80px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.875rem 1.75rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.15);
    color: white;
    border-color: rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

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

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

/* ============================================
   Features Section
   ============================================ */
.features {
    padding: 5rem 0;
    background: var(--bg-primary);
}

.section-title {
    text-align: center;
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 0.75rem;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.125rem;
    margin-bottom: 3rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--bg-primary);
    padding: 2rem;
    border-radius: var(--radius-xl);
    text-align: center;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: transparent;
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.7;
}

/* ============================================
   Section Common Styles
   ============================================ */
.section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-badge {
    display: inline-block;
    padding: 0.375rem 1rem;
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
    color: white;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 2rem;
    margin-bottom: 1rem;
}

.secondary-badge {
    background: linear-gradient(135deg, var(--secondary), var(--secondary-dark));
}

.dse-badge {
    background: linear-gradient(135deg, var(--accent), #DC2626);
}

.practice-badge {
    background: linear-gradient(135deg, #8B5CF6, #6D28D9);
}

.game-badge {
    background: linear-gradient(135deg, #EC4899, #BE185D);
}

/* ============================================
   Primary School Section
   ============================================ */
.primary-section {
    background: linear-gradient(180deg, var(--bg-primary) 0%, #EEF2FF 100%);
}

.curriculum-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.curriculum-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-left: 4px solid var(--primary);
}

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

.curriculum-level {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--primary);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 2rem;
    margin-bottom: 1rem;
}

.curriculum-card h3 {
    font-size: 1.375rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.curriculum-topics {
    margin-bottom: 1.5rem;
}

.curriculum-topics li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
    font-size: 0.9375rem;
}

.curriculum-topics li:last-child {
    border-bottom: none;
}

.curriculum-topics li::before {
    content: "✓";
    color: var(--secondary);
    margin-right: 0.5rem;
    font-weight: 700;
}

/* ============================================
   Secondary School Section
   ============================================ */
.secondary-section {
    background: linear-gradient(180deg, #ECFDF5 0%, var(--bg-primary) 100%);
}

.secondary-card {
    border-left-color: var(--secondary);
}

.secondary-card .curriculum-level {
    background: var(--secondary);
}

/* ============================================
   DSE Section
   ============================================ */
.dse-section {
    background: linear-gradient(180deg, var(--bg-primary) 0%, #FEF3C7 30%, #FEF3C7 70%, var(--bg-primary) 100%);
}

.dse-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.dse-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
}

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

.dse-card.core .dse-header {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
}

.dse-card.extended .dse-header {
    background: linear-gradient(135deg, var(--accent), #DC2626);
}

.dse-header {
    padding: 1.5rem;
    color: white;
}

.dse-type {
    font-size: 0.75rem;
    font-weight: 600;
    opacity: 0.9;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.dse-header h3 {
    font-size: 1.5rem;
    margin-top: 0.5rem;
}

.dse-content {
    padding: 1.5rem;
}

.dse-topics-group {
    margin-bottom: 1.25rem;
}

.dse-topics-group h4 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.dse-topics-group ul {
    padding-left: 1rem;
}

.dse-topics-group li {
    color: var(--text-primary);
    font-size: 0.9375rem;
    padding: 0.25rem 0;
    position: relative;
}

.dse-topics-group li::before {
    content: "•";
    color: var(--primary);
    position: absolute;
    left: -1rem;
}

.dse-card .btn {
    margin: 0 1.5rem 1.5rem;
    width: calc(100% - 3rem);
}

/* DSE Tips */
.dse-tips {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 2.5rem;
    box-shadow: var(--shadow);
}

.dse-tips h3 {
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
}

.tip-card {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
}

.tip-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--primary);
    color: white;
    font-weight: 700;
    font-size: 0.875rem;
    border-radius: 50%;
    flex-shrink: 0;
}

.tip-card p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
}

/* ============================================
   Practice Section
   ============================================ */
.practice-section {
    background: linear-gradient(180deg, #F5F3FF 0%, var(--bg-primary) 100%);
}

.practice-container {
    max-width: 800px;
    margin: 0 auto;
}

.practice-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    justify-content: center;
    align-items: flex-end;
}

.control-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.select-input {
    padding: 0.75rem 1rem;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    min-width: 180px;
    cursor: pointer;
    transition: var(--transition);
}

.select-input:focus {
    border-color: var(--primary);
}

.practice-area {
    margin-bottom: 2rem;
}

.question-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    min-height: 300px;
}

.question-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.question-number {
    font-weight: 600;
    color: var(--text-secondary);
}

.question-difficulty {
    padding: 0.25rem 0.75rem;
    background: var(--secondary);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 2rem;
}

.question-content {
    text-align: center;
    padding: 2rem 0;
}

.question-text {
    font-size: 1.5rem;
    color: var(--text-primary);
    line-height: 1.8;
}

.math-expression {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    margin: 1rem 0;
    font-family: 'Courier New', monospace;
}

.answer-section {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.answer-input {
    padding: 1rem 1.5rem;
    font-size: 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    width: 200px;
    text-align: center;
    transition: var(--transition);
}

.answer-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.btn-check {
    background: var(--secondary);
    color: white;
    padding: 1rem 2rem;
    font-size: 1rem;
}

.btn-check:hover {
    background: var(--secondary-dark);
}

.result-section {
    text-align: center;
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    margin-top: 1.5rem;
}

.result-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.result-text {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.result-section.correct {
    background: rgba(34, 197, 94, 0.1);
}

.result-section.correct .result-text {
    color: var(--success);
}

.result-section.wrong {
    background: rgba(239, 68, 68, 0.1);
}

.result-section.wrong .result-text {
    color: var(--danger);
}

.solution {
    background: var(--bg-secondary);
    padding: 1rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    text-align: left;
}

.solution h4 {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.solution p {
    color: var(--text-primary);
}

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

/* Score Board */
.score-board {
    display: flex;
    justify-content: center;
    gap: 2rem;
    padding: 1.5rem;
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
}

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

.score-label {
    display: block;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.score-value {
    font-size: 2rem;
    font-weight: 700;
}

.score-value.correct {
    color: var(--success);
}

.score-value.wrong {
    color: var(--danger);
}

.score-value.rate {
    color: var(--primary);
}

/* ============================================
   Game Section
   ============================================ */
.game-section {
    background: linear-gradient(180deg, var(--bg-primary) 0%, #FCE7F3 100%);
}

.game-container {
    max-width: 600px;
    margin: 0 auto;
}

.game-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
}

.timer {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--danger);
}

.timer-icon {
    margin-right: 0.5rem;
}

.game-score {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.game-score span {
    color: var(--primary);
    font-size: 1.5rem;
}

.game-area {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 3rem 2rem;
    text-align: center;
    box-shadow: var(--shadow-lg);
    min-height: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.game-start-screen h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.game-start-screen p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.btn-game-start {
    background: linear-gradient(135deg, #EC4899, #BE185D);
    color: white;
    padding: 1rem 2.5rem;
    font-size: 1.125rem;
}

.btn-game-start:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.game-question {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
}

.game-input {
    width: 150px;
    padding: 1rem;
    font-size: 2rem;
    text-align: center;
    border: 3px solid var(--border-color);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.game-input:focus {
    border-color: var(--primary);
}

.game-feedback {
    font-size: 1.5rem;
    margin-top: 1rem;
    height: 2rem;
}

.game-end-screen h3 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.final-score {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.final-score span {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary);
}

.score-message {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* ============================================
   Testimonials Section
   ============================================ */
.testimonials-section {
    padding: 5rem 0;
    background: var(--bg-secondary);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.testimonial-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.testimonial-content {
    margin-bottom: 1.5rem;
}

.testimonial-content p {
    color: var(--text-primary);
    font-size: 1rem;
    line-height: 1.8;
    font-style: italic;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.author-avatar {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    font-weight: 700;
    font-size: 1.25rem;
}

.author-name {
    display: block;
    font-weight: 600;
    color: var(--text-primary);
}

.author-role {
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* ============================================
   Contact Section
   ============================================ */
.contact-section {
    background: linear-gradient(135deg, #1F2937 0%, #111827 100%);
    color: white;
    padding: 5rem 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.contact-info > p {
    opacity: 0.8;
    margin-bottom: 2rem;
}

.contact-details {
    margin-bottom: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
    font-size: 1rem;
}

.contact-icon {
    font-size: 1.5rem;
}

.contact-hours h4 {
    font-size: 1rem;
    margin-bottom: 0.75rem;
    opacity: 0.9;
}

.contact-hours p {
    font-size: 0.9375rem;
    opacity: 0.7;
    margin-bottom: 0.25rem;
}

.contact-form-container {
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-xl);
    padding: 2rem;
}

.contact-form .form-group {
    margin-bottom: 1.25rem;
}

.contact-form label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    opacity: 0.9;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius);
    color: white;
    transition: var(--transition);
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
    color: rgba(255, 255, 255, 0.5);
}

.contact-form input:focus,
.contact-form textarea:focus {
    background: rgba(255, 255, 255, 0.15);
    border-color: var(--primary-light);
}

.btn-submit {
    width: 100%;
    margin-top: 0.5rem;
}

/* ============================================
   SEO Section
   ============================================ */
.seo-section {
    padding: 4rem 0;
    background: var(--bg-secondary);
}

.seo-content {
    max-width: 900px;
    margin: 0 auto;
}

.seo-content h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    text-align: center;
}

.seo-text {
    color: var(--text-secondary);
    line-height: 1.9;
}

.seo-text p {
    margin-bottom: 1.25rem;
    text-align: justify;
}

.seo-text strong {
    color: var(--text-primary);
}

.seo-keywords {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.seo-keywords span {
    padding: 0.5rem 1rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 2rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* ============================================
   Footer
   ============================================ */
.footer {
    background: #0F172A;
    color: white;
    padding: 4rem 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 3rem;
    padding-bottom: 3rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand {
    max-width: 300px;
}

.footer-brand .logo {
    margin-bottom: 1rem;
}

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

.footer-brand p {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9375rem;
    line-height: 1.7;
}

.footer-links h4 {
    font-size: 1rem;
    margin-bottom: 1.25rem;
    color: white;
}

.footer-links ul li {
    margin-bottom: 0.75rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.9375rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: white;
    padding-left: 5px;
}

.footer-social h4 {
    font-size: 1rem;
    margin-bottom: 1.25rem;
    color: white;
}

.social-links {
    display: flex;
    gap: 0.75rem;
}

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

.social-link svg {
    width: 20px;
    height: 20px;
    fill: white;
}

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

.footer-bottom {
    padding: 1.5rem 0;
    text-align: center;
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.875rem;
}

/* ============================================
   Responsive Styles
   ============================================ */
@media (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
}

@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-lg);
        transform: translateY(-150%);
        transition: var(--transition);
        opacity: 0;
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
    }

    .nav-link {
        display: block;
        text-align: center;
        padding: 1rem;
    }

    .hero-stats {
        gap: 1.5rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

    .footer-brand {
        max-width: 100%;
    }

    .footer-brand .logo {
        justify-content: center;
    }

    .social-links {
        justify-content: center;
    }

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

    .practice-controls {
        flex-direction: column;
        align-items: stretch;
    }

    .select-input {
        width: 100%;
    }

    .score-board {
        flex-direction: column;
        gap: 1rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .hero-cta {
        flex-direction: column;
        gap: 0.75rem;
    }

    .btn {
        width: 100%;
    }

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

    .question-card {
        padding: 1.5rem;
    }

    .math-expression {
        font-size: 2rem;
    }

    .game-question {
        font-size: 2rem;
    }

    .answer-section {
        flex-direction: column;
        align-items: center;
    }

    .answer-input {
        width: 100%;
    }
}

/* ============================================
   Animations
   ============================================ */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.fade-in {
    animation: fadeIn 0.5s ease-out;
}

.slide-up {
    animation: slideUp 0.6s ease-out;
}

/* Smooth scroll indicator for accessibility */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ============================================
   Breadcrumbs
   ============================================ */
.breadcrumbs {
    background: var(--bg-secondary);
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
}

.page-breadcrumbs {
    padding-top: 85px;
}

.breadcrumb-list {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.875rem;
}

.breadcrumb-list li {
    display: flex;
    align-items: center;
}

.breadcrumb-list li:not(:last-child)::after {
    content: "›";
    margin-left: 0.5rem;
    color: var(--text-light);
}

.breadcrumb-list a {
    color: var(--primary);
}

.breadcrumb-list a:hover {
    text-decoration: underline;
}

.breadcrumb-list li:last-child {
    color: var(--text-secondary);
}

/* ============================================
   Tool Intro Section
   ============================================ */
.tool-intro-section {
    background: var(--bg-secondary);
    padding: 3rem 0;
}

.tool-intro-content h2 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    text-align: center;
}

.intro-text {
    max-width: 900px;
    margin: 0 auto;
}

.intro-text p {
    color: var(--text-secondary);
    line-height: 1.9;
    margin-bottom: 1rem;
    text-align: justify;
}

.intro-text strong {
    color: var(--text-primary);
}

/* ============================================
   FAQ Section
   ============================================ */
.faq-section {
    background: var(--bg-primary);
    padding: 4rem 0;
}

.faq-container {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    margin-bottom: 1rem;
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 1.25rem 1.5rem;
    background: var(--bg-primary);
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    text-align: left;
    font-weight: 600;
    color: var(--text-primary);
    transition: var(--transition);
}

.faq-question:hover {
    background: var(--bg-secondary);
}

.faq-icon {
    width: 20px;
    height: 20px;
    transition: var(--transition);
    flex-shrink: 0;
    margin-left: 1rem;
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 1.5rem 1.5rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.faq-answer a {
    color: var(--primary);
}

.faq-answer a:hover {
    text-decoration: underline;
}

/* ============================================
   Latest Articles Section
   ============================================ */
.latest-articles-section {
    background: var(--bg-secondary);
    padding: 4rem 0;
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.article-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.article-image {
    height: 160px;
    overflow: hidden;
}

.article-placeholder-img {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
}

.article-content {
    padding: 1.5rem;
}

.article-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(79, 70, 229, 0.1);
    color: var(--primary);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 2rem;
    margin-bottom: 0.75rem;
}

.article-content h3 {
    font-size: 1.125rem;
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.article-content h3 a {
    color: var(--text-primary);
}

.article-content h3 a:hover {
    color: var(--primary);
}

.article-content p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.read-more {
    color: var(--primary);
    font-weight: 600;
    font-size: 0.875rem;
}

.read-more:hover {
    text-decoration: underline;
}

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

/* ============================================
   Blog Pages
   ============================================ */
.blog-header {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    padding: 4rem 0 3rem;
    text-align: center;
}

.blog-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.blog-header p {
    opacity: 0.9;
}

.blog-content {
    padding: 3rem 0;
}

.blog-categories {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
    margin-bottom: 2.5rem;
}

.category-btn {
    padding: 0.5rem 1.25rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 2rem;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

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

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.blog-card {
    background: var(--bg-primary);
    border-radius: var(--radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.blog-card-image {
    height: 180px;
}

.blog-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
}

.blog-card-content {
    padding: 1.5rem;
}

.blog-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(79, 70, 229, 0.1);
    color: var(--primary);
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 2rem;
    margin-bottom: 0.75rem;
}

.blog-card-content h2 {
    font-size: 1.125rem;
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.blog-card-content h2 a {
    color: var(--text-primary);
}

.blog-card-content h2 a:hover {
    color: var(--primary);
}

.blog-card-content p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.blog-meta {
    display: flex;
    gap: 1rem;
    font-size: 0.8125rem;
    color: var(--text-light);
    margin-bottom: 1rem;
}

.blog-cta {
    text-align: center;
    padding: 3rem;
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
}

.blog-cta h2 {
    margin-bottom: 0.75rem;
}

.blog-cta p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

/* ============================================
   Article Pages
   ============================================ */
.article-content {
    padding: 2rem 0 4rem;
}

.blog-article {
    max-width: 800px;
    margin: 0 auto;
}

.article-header {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.article-header h1 {
    font-size: 2rem;
    line-height: 1.3;
    margin: 0.75rem 0;
}

.article-meta {
    display: flex;
    gap: 1.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.article-body {
    line-height: 1.9;
}

.article-body .lead {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.article-body h2 {
    font-size: 1.5rem;
    margin: 2.5rem 0 1rem;
    color: var(--text-primary);
}

.article-body h3 {
    font-size: 1.25rem;
    margin: 2rem 0 0.75rem;
    color: var(--text-primary);
}

.article-body p {
    margin-bottom: 1.25rem;
    color: var(--text-primary);
}

.article-body ul, .article-body ol {
    margin: 1rem 0 1.5rem 1.5rem;
}

.article-body li {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.article-body a {
    color: var(--primary);
}

.article-body a:hover {
    text-decoration: underline;
}

.example-box {
    background: var(--bg-secondary);
    border-left: 4px solid var(--primary);
    padding: 1.5rem;
    margin: 1.5rem 0;
    border-radius: 0 var(--radius) var(--radius) 0;
}

.example-box h4 {
    color: var(--primary);
    margin-bottom: 0.75rem;
}

.highlight {
    background: rgba(79, 70, 229, 0.1);
    padding: 0.125rem 0.375rem;
    border-radius: 0.25rem;
}

.article-cta {
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
    color: white;
    padding: 2rem;
    border-radius: var(--radius-xl);
    text-align: center;
    margin: 3rem 0;
}

.article-cta h3 {
    margin-bottom: 0.75rem;
}

.article-cta p {
    opacity: 0.9;
    margin-bottom: 1.5rem;
}

.article-cta a {
    color: white;
}

.article-cta .btn {
    background: white;
    color: var(--primary);
}

.article-footer {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.article-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    align-items: center;
}

.article-tags span {
    color: var(--text-secondary);
}

.article-tags a {
    padding: 0.25rem 0.75rem;
    background: var(--bg-secondary);
    border-radius: 2rem;
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

.article-tags a:hover {
    background: var(--primary);
    color: white;
}

.related-articles {
    margin-top: 4rem;
}

.related-articles h2 {
    margin-bottom: 1.5rem;
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.related-card {
    display: block;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.related-card:hover {
    background: var(--primary);
    color: white;
}

.related-card h3 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.related-card p {
    font-size: 0.875rem;
    opacity: 0.8;
}

/* ============================================
   Legal Pages
   ============================================ */
.page-content {
    padding: 2rem 0 4rem;
    min-height: 60vh;
}

.legal-content {
    max-width: 800px;
    margin: 0 auto;
}

.legal-content h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.last-updated {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 2rem;
}

.legal-content section {
    margin-bottom: 2rem;
}

.legal-content h2 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.legal-content h3 {
    font-size: 1.0625rem;
    margin: 1.5rem 0 0.75rem;
    color: var(--text-primary);
}

.legal-content p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.legal-content ul {
    margin: 1rem 0 1rem 1.5rem;
    list-style: disc;
}

.legal-content li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.legal-content a {
    color: var(--primary);
}

/* ============================================
   About Page
   ============================================ */
.about-hero {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    padding: 4rem 0 3rem;
    text-align: center;
    margin-top: 70px;
}

.about-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.about-tagline {
    font-size: 1.25rem;
    opacity: 0.9;
}

.about-content {
    padding: 3rem 0;
}

.about-section {
    margin-bottom: 4rem;
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.about-grid.reverse {
    direction: rtl;
}

.about-grid.reverse > * {
    direction: ltr;
}

.about-text h2 {
    font-size: 1.75rem;
    margin-bottom: 1rem;
}

.about-text p {
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.about-text ul {
    margin: 1rem 0 1rem 1.5rem;
}

.about-text li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.about-icon-box {
    display: flex;
    align-items: center;
    justify-content: center;
}

.icon-large {
    font-size: 8rem;
}

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

.values-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.value-card {
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: var(--radius-xl);
    text-align: center;
}

.value-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.value-card h3 {
    margin-bottom: 0.75rem;
}

.value-card p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.offerings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.offering-card {
    padding: 2rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
}

.offering-card h3 {
    margin-bottom: 1rem;
}

.offering-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.parents-section {
    background: var(--bg-secondary);
    padding: 3rem;
    border-radius: var(--radius-xl);
}

.about-cta {
    text-align: center;
    padding: 3rem;
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
    color: white;
    border-radius: var(--radius-xl);
}

.about-cta h2 {
    margin-bottom: 0.75rem;
}

.about-cta p {
    opacity: 0.9;
    margin-bottom: 1.5rem;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.about-cta .btn-primary {
    background: white;
    color: var(--primary);
}

.about-cta .btn-secondary {
    border-color: white;
    color: white;
}

/* ============================================
   Navigation Dropdown
   ============================================ */
.nav-dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    min-width: 180px;
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition);
}

.nav-dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-menu a {
    display: block;
    padding: 0.75rem 1rem;
    color: var(--text-secondary);
}

.dropdown-menu a:hover {
    background: var(--bg-secondary);
    color: var(--primary);
}

/* Simple Table */
.simple-table {
    width: 100%;
    border-collapse: collapse;
    margin: 1.5rem 0;
}

.simple-table th,
.simple-table td {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    text-align: left;
}

.simple-table th {
    background: var(--bg-secondary);
    font-weight: 600;
}

/* Responsive for new sections */
@media (max-width: 768px) {
    .about-grid {
        grid-template-columns: 1fr;
    }

    .about-grid.reverse {
        direction: ltr;
    }

    .icon-large {
        font-size: 5rem;
    }

    .about-hero {
        margin-top: 70px;
        padding: 3rem 0 2rem;
    }

    .about-hero h1 {
        font-size: 1.75rem;
    }

    .blog-header h1 {
        font-size: 1.75rem;
    }

    .article-header h1 {
        font-size: 1.5rem;
    }

    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        padding-left: 1rem;
    }
}