/**
 * 한국 작명 도우미 - 스타일시트
 * Design: Soft Modern Korean
 */

:root {
    --primary: #7c3aed;
    --primary-light: #a78bfa;
    --secondary: #ec4899;
    --accent: #14b8a6;
    --background: #fefce8;
    --background-soft: #fef9c3;
    --foreground: #1f2937;
    --muted: #6b7280;
    --border: rgba(0,0,0,0.08);
    --card-bg: rgba(255,255,255,0.7);
    --radius: 1rem;
    --shadow: 0 4px 20px rgba(0,0,0,0.08);
}

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

body {
    font-family: 'Pretendard Variable', -apple-system, BlinkMacSystemFont, sans-serif;
    background: linear-gradient(135deg, var(--background) 0%, #fff7ed 100%);
    color: var(--foreground);
    min-height: 100vh;
    line-height: 1.6;
}

a {
    text-decoration: none;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 640px) {
    .container { padding: 0 1.5rem; }
}

@media (min-width: 1024px) {
    .container { padding: 0 2rem; }
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    background: rgba(255,255,255,0.8);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.logo-icon {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.logo-icon.small {
    width: 32px;
    height: 32px;
    border-radius: 8px;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav {
    display: none;
    align-items: center;
    gap: 1.5rem;
}

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

.nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--muted);
    text-decoration: none;
    transition: color 0.2s;
}

.nav-link:hover,
.nav-link.active {
    color: var(--foreground);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.625rem 1.25rem;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    color: white;
    box-shadow: 0 4px 14px rgba(124, 58, 237, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(124, 58, 237, 0.4);
}

.btn-secondary {
    background: white;
    color: var(--foreground);
    border: 1px solid var(--border);
}

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

.btn-outline {
    background: transparent;
    color: var(--foreground);
    border: 1px solid var(--border);
}

.btn-outline:hover {
    background: rgba(0,0,0,0.05);
}

/* Cards */
.card {
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.card-hover:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 30px rgba(0,0,0,0.12);
}

/* Hero Section */
.hero {
    padding-top: 120px;
    padding-bottom: 80px;
    position: relative;
    overflow: hidden;
}

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

@media (min-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr 1fr;
    }
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}

@media (min-width: 768px) {
    .hero-title { font-size: 3.5rem; }
}

.hero-title .highlight {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--muted);
    margin-bottom: 2rem;
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
}

.stat-item {
    text-align: left;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--muted);
}

.hero-image {
    display: flex;
    justify-content: center;
}

.hero-image img {
    max-width: 400px;
    width: 100%;
    height: auto;
}

/* Decorative Blobs */
.blob {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.5;
    z-index: -1;
}

.blob-1 {
    width: 300px;
    height: 300px;
    background: var(--accent);
    bottom: 0;
    left: -100px;
}

.blob-2 {
    width: 400px;
    height: 400px;
    background: var(--primary-light);
    top: 100px;
    right: -150px;
}

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

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

.section-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 9999px;
    font-size: 0.875rem;
    color: var(--muted);
    margin-bottom: 1rem;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.section-title .highlight {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-description {
    color: var(--muted);
    max-width: 600px;
    margin: 0 auto;
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(1, 1fr);
    gap: 1.5rem;
}

@media (min-width: 768px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
    .features-grid { grid-template-columns: repeat(4, 1fr); }
}

.feature-card {
    padding: 2rem;
    transition: all 0.3s;
}

.feature-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    color: white;
}

.feature-icon.purple { background: linear-gradient(135deg, #8b5cf6, #7c3aed); }
.feature-icon.green { background: linear-gradient(135deg, #10b981, #059669); }
.feature-icon.orange { background: linear-gradient(135deg, #f97316, #ea580c); }
.feature-icon.pink { background: linear-gradient(135deg, #ec4899, #db2777); }

.feature-title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.feature-description {
    font-size: 0.875rem;
    color: var(--muted);
    margin-bottom: 1rem;
}

.feature-link {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--primary);
    text-decoration: none;
}

.feature-link:hover {
    opacity: 0.8;
}

/* Names Grid */
.names-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

@media (min-width: 768px) {
    .names-grid { grid-template-columns: repeat(5, 1fr); }
}

.name-card {
    padding: 1.25rem;
    text-align: center;
    transition: all 0.3s;
}

.name-rank {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--muted);
    margin-bottom: 0.5rem;
}

.name-text {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.name-count {
    font-size: 0.75rem;
    color: var(--muted);
}

.gender-badge {
    display: inline-block;
    padding: 0.125rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.625rem;
    font-weight: 600;
    margin-left: 0.25rem;
}

.gender-male { background: #dbeafe; color: #1d4ed8; }
.gender-female { background: #fce7f3; color: #be185d; }
.gender-unisex { background: #fef3c7; color: #b45309; }

/* Surnames Section */
.surnames-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

@media (min-width: 768px) {
    .surnames-grid { grid-template-columns: repeat(5, 1fr); }
}

.surname-card {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
}

.surname-rank {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: 600;
    color: white;
}

.surname-rank.gold { background: linear-gradient(135deg, #fbbf24, #d97706); }
.surname-rank.silver { background: linear-gradient(135deg, #9ca3af, #6b7280); }
.surname-rank.bronze { background: linear-gradient(135deg, #f97316, #c2410c); }

.surname-info {
    flex: 1;
}

.surname-name {
    font-size: 1.125rem;
    font-weight: 600;
}

.surname-hanja {
    font-size: 0.875rem;
    color: var(--muted);
}

.surname-stats {
    text-align: right;
}

.surname-population {
    font-size: 0.875rem;
    font-weight: 600;
}

.surname-percentage {
    font-size: 0.75rem;
    color: var(--muted);
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    padding: 4rem 0;
    text-align: center;
    color: white;
    border-radius: var(--radius);
    margin: 2rem;
}

.cta-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.cta-description {
    opacity: 0.9;
    margin-bottom: 2rem;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

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

.cta-button:hover {
    background: var(--background);
}

/* Footer */
.footer {
    background: var(--card-bg);
    border-top: 1px solid var(--border);
    padding: 2rem 0;
    margin-top: 4rem;
}

.footer-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
    text-align: center;
}

@media (min-width: 768px) {
    .footer-inner {
        flex-direction: row;
        justify-content: space-between;
        text-align: left;
    }
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.footer-links a {
    font-size: 0.875rem;
    color: var(--muted);
    text-decoration: none;
}

.footer-links a:hover {
    color: var(--foreground);
}

.footer-source {
    font-size: 0.875rem;
    color: var(--muted);
}

/* Page Header */
.page-header {
    padding-top: 100px;
    padding-bottom: 2rem;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    font-size: 0.875rem;
    color: var(--muted);
    text-decoration: none;
    margin-bottom: 1rem;
}

.back-link:hover {
    color: var(--foreground);
}

.page-title-wrapper {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.page-icon {
    width: 48px;
    height: 48px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
}

.page-description {
    color: var(--muted);
}

/* Generator Page */
.generator-layout {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 2rem 0;
}

@media (min-width: 1024px) {
    .generator-layout {
        grid-template-columns: 350px 1fr;
    }
}

.generator-sidebar {
    position: sticky;
    top: 80px;
    height: fit-content;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.form-input,
.form-select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    font-size: 1rem;
    background: white;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-input:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.1);
}

/* Searchable Select */
.searchable-select {
    position: relative;
}

.searchable-select-input {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    font-size: 1rem;
    background: white;
    cursor: pointer;
}

.searchable-select-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.1);
}

.searchable-select-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    max-height: 300px;
    overflow-y: auto;
    z-index: 100;
    display: none;
}

.searchable-select-dropdown.open {
    display: block;
}

.searchable-select-search {
    padding: 0.75rem;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    background: white;
}

.searchable-select-search input {
    width: 100%;
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: 0.375rem;
    font-size: 0.875rem;
}

.searchable-select-search input:focus {
    outline: none;
    border-color: var(--primary);
}

.searchable-select-option {
    padding: 0.75rem 1rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.15s;
}

.searchable-select-option:hover {
    background: var(--background-soft);
}

.searchable-select-option.selected {
    background: rgba(124, 58, 237, 0.1);
    color: var(--primary);
}

.searchable-select-option-hanja {
    font-size: 0.875rem;
    color: var(--muted);
}

/* Radio Group */
.radio-group {
    display: flex;
    gap: 0.5rem;
}

.radio-option {
    flex: 1;
}

.radio-option input {
    display: none;
}

.radio-option label {
    display: block;
    padding: 0.625rem 1rem;
    text-align: center;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.radio-option input:checked + label {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* Generated Names */
.generated-names {
    display: grid;
    grid-template-columns: repeat(1, 1fr);
    gap: 1rem;
}

@media (min-width: 640px) {
    .generated-names { grid-template-columns: repeat(2, 1fr); }
}

.generated-name-card {
    padding: 1.5rem;
}

.generated-name-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 0.5rem;
}

.generated-name-text {
    font-size: 1.5rem;
    font-weight: 700;
}

.generated-name-hanja {
    font-size: 0.875rem;
    color: var(--muted);
    margin-bottom: 0.5rem;
}

.generated-name-meaning {
    font-size: 0.875rem;
    color: var(--muted);
    padding: 0.75rem;
    background: var(--background-soft);
    border-radius: 0.5rem;
    margin-bottom: 1rem;
}

.generated-name-actions {
    display: flex;
    gap: 0.5rem;
}

.generated-name-actions button {
    flex: 1;
    padding: 0.5rem;
    font-size: 0.875rem;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
}

.empty-state-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--background-soft);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: var(--muted);
}

.empty-state-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.empty-state-description {
    color: var(--muted);
    margin-bottom: 1.5rem;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.5rem;
}

.tab {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--muted);
    background: none;
    border: none;
    cursor: pointer;
    border-radius: 0.5rem;
    transition: all 0.2s;
}

.tab:hover {
    color: var(--foreground);
    background: var(--background-soft);
}

.tab.active {
    color: var(--primary);
    background: rgba(124, 58, 237, 0.1);
}

/* Filter Pills */
.filter-pills {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

.filter-pill {
    padding: 0.375rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 500;
    border: 1px solid var(--border);
    border-radius: 9999px;
    background: white;
    cursor: pointer;
    transition: all 0.2s;
}

.filter-pill:hover {
    border-color: var(--primary);
}

.filter-pill.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* Search Input */
.search-input-wrapper {
    position: relative;
    margin-bottom: 1.5rem;
}

.search-input-wrapper svg {
    position: absolute;
    left: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--muted);
}

.search-input {
    width: 100%;
    padding: 0.75rem 1rem 0.75rem 2.75rem;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    font-size: 1rem;
    background: white;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.1);
}

/* Ranking List */
.ranking-list {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.ranking-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.25rem;
}

.ranking-position {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    font-size: 0.875rem;
}

.ranking-position.top-1 { background: linear-gradient(135deg, #fbbf24, #d97706); color: white; }
.ranking-position.top-2 { background: linear-gradient(135deg, #9ca3af, #6b7280); color: white; }
.ranking-position.top-3 { background: linear-gradient(135deg, #f97316, #c2410c); color: white; }
.ranking-position.default { background: var(--background-soft); color: var(--muted); }

.ranking-info {
    flex: 1;
}

.ranking-name {
    font-size: 1.125rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.ranking-stats {
    text-align: right;
}

.ranking-count {
    font-weight: 600;
}

.ranking-label {
    font-size: 0.75rem;
    color: var(--muted);
}

/* Hanja Grid */
.hanja-section {
    margin-bottom: 2rem;
}

.hanja-section-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.hanja-section-badge {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.875rem;
    font-weight: 600;
}

.hanja-section-title {
    font-size: 1rem;
    font-weight: 600;
}

.hanja-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
}

@media (min-width: 640px) {
    .hanja-grid { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 1024px) {
    .hanja-grid { grid-template-columns: repeat(4, 1fr); }
}

.hanja-card {
    text-align: center;
    padding: 1.5rem 1rem;
}

.hanja-character {
    font-size: 2.5rem;
    font-weight: 400;
    margin-bottom: 0.5rem;
}

.hanja-sound {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.hanja-meaning {
    font-size: 0.75rem;
    color: var(--muted);
    margin-bottom: 0.5rem;
}

.hanja-strokes {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.25rem 0.5rem;
    background: var(--background-soft);
    border-radius: 9999px;
    font-size: 0.75rem;
    color: var(--muted);
}

/* Data Download */
.data-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 768px) {
    .data-grid { grid-template-columns: repeat(2, 1fr); }
}

.data-card {
    padding: 1.5rem;
}

.data-card-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1rem;
}

.data-icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.data-icon.json { background: #fef3c7; color: #b45309; }
.data-icon.csv { background: #d1fae5; color: #059669; }

.data-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.data-badges {
    display: flex;
    gap: 0.5rem;
}

.data-badge {
    padding: 0.125rem 0.5rem;
    font-size: 0.625rem;
    font-weight: 600;
    border-radius: 9999px;
    background: var(--background-soft);
    color: var(--muted);
}

.data-description {
    font-size: 0.875rem;
    color: var(--muted);
    margin-bottom: 1rem;
}

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

.data-records {
    font-size: 0.875rem;
    color: var(--muted);
}

/* Info Card */
.info-card {
    display: flex;
    gap: 1rem;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.info-icon {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    background: #dbeafe;
    color: #2563eb;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.info-content h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.info-content p {
    font-size: 0.875rem;
    color: var(--muted);
}

/* Data Structure */
.data-structure {
    margin-top: 2rem;
}

.data-structure h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.data-structure-description {
    color: var(--muted);
    margin-bottom: 1.5rem;
}

.data-structure-section {
    margin-bottom: 1.5rem;
}

.data-structure-section h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.data-structure-code {
    background: var(--background-soft);
    border-radius: 0.5rem;
    padding: 1rem;
    font-family: monospace;
    font-size: 0.875rem;
}

.data-structure-code div {
    margin-bottom: 0.25rem;
}

.data-structure-code span {
    color: var(--primary);
}

/* Utilities */
.text-center { text-align: center; }
.mt-4 { margin-top: 1rem; }
.mt-8 { margin-top: 2rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-8 { margin-bottom: 2rem; }

/* Toast */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    padding: 1rem 1.5rem;
    background: var(--foreground);
    color: white;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    z-index: 1000;
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}