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

:root {
    --dida-dark: #1a1a2e;
    --dida-navy: #16213e;
    --dida-blue: #0f3460;
    --dida-accent: #e94560;
    --dida-light: #f8f9fa;
    --dida-white: #ffffff;
    --dida-gray: #6c757d;
    --dida-border: #e9ecef;
    --dida-card-bg: #ffffff;
    --dida-text: #2d3436;
    --dida-text-light: #636e72;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--dida-text);
    background-color: var(--dida-white);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(26, 26, 46, 0.95);
    backdrop-filter: blur(20px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    height: 72px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    transition: var(--transition);
}

.logo:hover {
    opacity: 0.9;
}

.logo-img {
    height: 32px;
    width: auto;
}

.logo-text {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--dida-white);
    letter-spacing: 0.02em;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2.5rem;
}

.nav-links a {
    text-decoration: none;
    color: rgba(255, 255, 255, 0.75);
    font-size: 0.9rem;
    font-weight: 400;
    letter-spacing: 0.02em;
    transition: var(--transition);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--dida-accent);
    transition: width 0.3s ease;
}

.nav-links a:hover {
    color: var(--dida-white);
}

.nav-links a:hover::after {
    width: 100%;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8rem 2rem 4rem;
    background: linear-gradient(135deg, var(--dida-dark) 0%, var(--dida-navy) 50%, var(--dida-blue) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 30%, rgba(233, 69, 96, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(15, 52, 96, 0.3) 0%, transparent 50%);
    pointer-events: none;
}

.hero::after {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(233, 69, 96, 0.05) 0%, transparent 70%);
    pointer-events: none;
}

.hero-content {
    max-width: 800px;
    text-align: center;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: clamp(2.5rem, 5vw, 3.8rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
    letter-spacing: 0.02em;
    color: var(--dida-white);
}

.hero-subtitle {
    font-size: 1.1rem;
    font-weight: 300;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--dida-accent);
    margin-bottom: 1.5rem;
}

.hero-desc {
    font-size: 1.05rem;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 3rem;
    line-height: 1.8;
    font-weight: 300;
}

/* Search Bar */
.search-container {
    position: relative;
    max-width: 600px;
    margin: 0 auto;
}

.search-input {
    width: 100%;
    padding: 1.2rem 3.5rem 1.2rem 1.5rem;
    font-size: 1rem;
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.08);
    color: var(--dida-white);
    transition: var(--transition);
    font-family: inherit;
    backdrop-filter: blur(10px);
}

.search-input::placeholder {
    color: rgba(255, 255, 255, 0.4);
}

.search-input:focus {
    outline: none;
    border-color: var(--dida-accent);
    background: rgba(255, 255, 255, 0.12);
    box-shadow: 0 0 0 4px rgba(233, 69, 96, 0.15);
}

.search-icon {
    position: absolute;
    right: 1.5rem;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.5rem;
    color: rgba(255, 255, 255, 0.4);
    pointer-events: none;
}

/* Features Section */
.features {
    padding: 5rem 2rem;
    background: var(--dida-light);
}

.features-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2.5rem;
}

.feature-item {
    text-align: center;
    padding: 2.5rem 2rem;
    background: var(--dida-white);
    border-radius: 12px;
    transition: var(--transition);
    border: 1px solid var(--dida-border);
}

.feature-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

.feature-number {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--dida-accent);
    margin-bottom: 1.2rem;
    padding: 4px 12px;
    background: rgba(233, 69, 96, 0.08);
    border-radius: 20px;
}

.feature-item h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.8rem;
    color: var(--dida-dark);
}

.feature-item p {
    color: var(--dida-text-light);
    line-height: 1.7;
    font-size: 0.95rem;
}

/* Glossary Section */
.glossary {
    padding: 5rem 2rem;
    background: var(--dida-white);
}

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

.section-title {
    font-family: 'Noto Sans SC', sans-serif;
    font-size: clamp(1.8rem, 3.5vw, 2.5rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: 0.5rem;
    color: var(--dida-dark);
}

.section-subtitle {
    text-align: center;
    font-size: 0.85rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--dida-accent);
    margin-bottom: 2.5rem;
    font-weight: 500;
}

/* Category Filter */
.category-filter {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 2.5rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.6rem 1.2rem;
    border: 1px solid var(--dida-border);
    background: var(--dida-white);
    color: var(--dida-text-light);
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
    border-radius: 6px;
    font-family: inherit;
    font-weight: 400;
}

.filter-btn:hover {
    border-color: var(--dida-accent);
    color: var(--dida-accent);
}

.filter-btn.active {
    background: var(--dida-dark);
    color: var(--dida-white);
    border-color: var(--dida-dark);
}

/* Glossary Table */
.glossary-table {
    background: var(--dida-white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06);
    border: 1px solid var(--dida-border);
}

.table-header {
    display: grid;
    grid-template-columns: 1fr 1.2fr 120px;
    padding: 1.2rem 2rem;
    background: var(--dida-dark);
    color: var(--dida-white);
    font-weight: 500;
    font-size: 0.85rem;
    letter-spacing: 0.05em;
}

.table-body {
    max-height: 600px;
    overflow-y: auto;
}

.table-row {
    display: grid;
    grid-template-columns: 1fr 1.2fr 120px;
    padding: 1rem 2rem;
    border-bottom: 1px solid var(--dida-border);
    transition: var(--transition);
    cursor: pointer;
}

.table-row:hover {
    background: var(--dida-light);
}

.table-row:last-child {
    border-bottom: none;
}

.table-row span {
    font-size: 0.9rem;
    color: var(--dida-text);
}

.table-row .category {
    color: var(--dida-accent);
    font-size: 0.8rem;
    font-weight: 500;
}

/* About Section */
.about {
    padding: 5rem 2rem;
    background: var(--dida-light);
}

.about-container {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content {
    margin-top: 2rem;
}

.about-content p {
    color: var(--dida-text-light);
    line-height: 1.8;
    margin-bottom: 1rem;
    font-size: 1rem;
}

/* Footer */
.footer {
    padding: 3rem 2rem;
    background: var(--dida-dark);
    color: var(--dida-white);
}

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

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-logo-img {
    height: 28px;
    width: auto;
    filter: brightness(0) invert(1);
}

.footer-info {
    text-align: right;
}

.footer-info p {
    margin: 0.3rem 0;
    font-size: 0.85rem;
    opacity: 0.7;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-links {
        gap: 1.5rem;
    }
    
    .logo-text {
        font-size: 0.8rem;
    }
    
    .hero-title {
        font-size: 2.2rem;
    }
    
    .features-container {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .table-header,
    .table-row {
        grid-template-columns: 1fr 1fr;
    }
    
    .table-header span:last-child,
    .table-row .category {
        display: none;
    }
    
    .footer-content {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
    
    .footer-info {
        text-align: center;
    }
}

/* Table Footer */
.table-footer {
    padding: 1rem 2rem;
    background: var(--dida-light);
    border-top: 1px solid var(--dida-border);
    text-align: right;
    font-size: 0.85rem;
    color: var(--dida-text-light);
}

/* Scrollbar Styling */
.table-body::-webkit-scrollbar {
    width: 6px;
}

.table-body::-webkit-scrollbar-track {
    background: var(--dida-light);
}

.table-body::-webkit-scrollbar-thumb {
    background: var(--dida-border);
    border-radius: 3px;
}

.table-body::-webkit-scrollbar-thumb:hover {
    background: var(--dida-gray);
}