/**
 * Word Anagram Game - Main Stylesheet
 * Cosmic Theme with Melon-inspired Design
 * aw.soritune.com
 */

/* ========================================
   CSS Variables - Cosmic Color Scheme
======================================== */
:root {
    /* Primary Colors - Cosmic */
    --color-primary: #03C75A;
    --color-primary-dark: #02a34a;
    --color-primary-light: #00e676;
    --color-secondary: #667eea;
    --color-accent: #764ba2;

    /* Background Colors */
    --color-bg-primary: #0a0a1a;
    --color-bg-secondary: #121225;
    --color-bg-card: #1a1a35;
    --color-bg-card-hover: #252550;
    --color-bg-surface: rgba(26, 26, 53, 0.9);

    /* Text Colors */
    --color-text-primary: #ffffff;
    --color-text-secondary: #b4b4d0;
    --color-text-tertiary: #7a7a9d;
    --color-text-muted: #5a5a7d;

    /* Gradient */
    --gradient-primary: linear-gradient(135deg, #03C75A 0%, #00e676 100%);
    --gradient-cosmic: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-dark: linear-gradient(180deg, #0a0a1a 0%, #121225 100%);
    --gradient-card: linear-gradient(145deg, #1a1a35 0%, #252550 100%);
    --gradient-glow: radial-gradient(circle at 50% 50%, rgba(3, 199, 90, 0.2) 0%, transparent 70%);

    /* Status Colors */
    --color-success: #03C75A;
    --color-error: #ff4757;
    --color-warning: #ffa502;
    --color-info: #3498db;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 40px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px rgba(3, 199, 90, 0.3);
    --shadow-cosmic: 0 0 40px rgba(102, 126, 234, 0.3);

    /* Spacing */
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Typography */
    --font-family: 'Pretendard', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
    --font-size-xs: 12px;
    --font-size-sm: 14px;
    --font-size-md: 16px;
    --font-size-lg: 18px;
    --font-size-xl: 20px;
    --font-size-2xl: 24px;
    --font-size-3xl: 32px;
    --font-size-4xl: 40px;
    --font-size-5xl: 48px;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;

    /* Z-index */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-modal: 300;
    --z-overlay: 400;
    --z-toast: 500;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-md);
    line-height: 1.6;
    color: var(--color-text-primary);
    background: var(--color-bg-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Animated Background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(ellipse at 20% 20%, rgba(102, 126, 234, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(118, 75, 162, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(3, 199, 90, 0.1) 0%, transparent 60%);
    z-index: -1;
    animation: bgPulse 20s ease-in-out infinite;
}

@keyframes bgPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

ul, ol {
    list-style: none;
}

/* ========================================
   Typography
======================================== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--color-text-primary);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-md); }

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ========================================
   Layout
======================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

.container-sm { max-width: 800px; }
.container-lg { max-width: 1400px; }

/* ========================================
   Header
======================================== */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-sticky);
    background: rgba(10, 10, 26, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-normal);
}

.site-header.scrolled {
    background: rgba(10, 10, 26, 0.98);
    box-shadow: var(--shadow-md);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
    padding: 0 var(--space-lg);
    max-width: 1400px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: var(--font-size-xl);
    font-weight: 800;
    color: var(--color-text-primary);
}

.logo-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    font-size: 20px;
}

.logo-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Main Navigation */
.main-nav {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.main-nav a {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-md);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: var(--transition-normal);
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--color-text-primary);
    background: rgba(255, 255, 255, 0.1);
}

.main-nav a.active {
    background: var(--gradient-primary);
    color: #000;
}

.nav-icon {
    width: 20px;
    height: 20px;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--space-sm);
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text-primary);
    transition: var(--transition-normal);
}

/* ========================================
   Mobile Navigation
======================================== */
.mobile-nav {
    display: none;
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(10, 10, 26, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: var(--z-modal);
    padding: var(--space-lg);
    overflow-y: auto;
}

.mobile-nav.active {
    display: block;
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.mobile-nav a {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-md);
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.mobile-nav a:hover,
.mobile-nav a.active {
    color: var(--color-primary);
    background: rgba(3, 199, 90, 0.1);
}

/* ========================================
   Main Content
======================================== */
.site-main {
    min-height: calc(100vh - 70px);
    padding-top: 70px;
}

/* ========================================
   Hero Section
======================================== */
.hero-section {
    position: relative;
    padding: var(--space-3xl) 0;
    overflow: hidden;
    min-height: 80vh;
    display: flex;
    align-items: center;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 900;
    margin-bottom: var(--space-lg);
    line-height: 1.2;
}

.hero-title span {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--color-text-secondary);
    margin-bottom: var(--space-2xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

/* ========================================
   Buttons
======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-full);
    font-size: var(--font-size-md);
    font-weight: 600;
    transition: var(--transition-normal);
    cursor: pointer;
    border: none;
    text-decoration: none;
}

.btn-primary {
    background: var(--gradient-primary);
    color: #000;
    box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 40px rgba(3, 199, 90, 0.5);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: var(--color-text-primary);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

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

.btn-cosmic {
    background: var(--gradient-cosmic);
    color: #fff;
    box-shadow: var(--shadow-cosmic);
}

.btn-cosmic:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 40px rgba(102, 126, 234, 0.5);
}

.btn-lg {
    padding: var(--space-lg) var(--space-2xl);
    font-size: var(--font-size-lg);
}

.btn-sm {
    padding: var(--space-sm) var(--space-md);
    font-size: var(--font-size-sm);
}

.btn-icon {
    width: 44px;
    height: 44px;
    padding: 0;
    border-radius: var(--radius-full);
}

/* ========================================
   Cards
======================================== */
.card {
    background: var(--color-bg-card);
    border-radius: var(--radius-lg);
    padding: var(--space-lg);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-normal);
}

.card:hover {
    background: var(--color-bg-card-hover);
    border-color: rgba(255, 255, 255, 0.1);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.card-glow {
    position: relative;
}

.card-glow::before {
    content: '';
    position: absolute;
    inset: -1px;
    border-radius: inherit;
    background: var(--gradient-primary);
    opacity: 0;
    z-index: -1;
    transition: var(--transition-normal);
}

.card-glow:hover::before {
    opacity: 0.3;
    filter: blur(20px);
}

/* ========================================
   Game Section
======================================== */
.game-container {
    max-width: 600px;
    margin: 0 auto;
    padding: var(--space-2xl) var(--space-md);
}

.game-card {
    background: var(--gradient-card);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    border: 1px solid rgba(255, 255, 255, 0.1);
    position: relative;
    overflow: hidden;
}

.game-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
}

/* Game Header */
.game-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-xl);
}

.game-stats {
    display: flex;
    gap: var(--space-lg);
}

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

.stat-value {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-primary);
}

.stat-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Scrambled Word Display */
.word-display {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.scrambled-word {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-lg);
    flex-wrap: wrap;
}

.letter-tile {
    width: 56px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg-secondary);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    font-size: var(--font-size-2xl);
    font-weight: 700;
    text-transform: uppercase;
    color: var(--color-text-primary);
    transition: var(--transition-normal);
    cursor: pointer;
    user-select: none;
}

.letter-tile:hover {
    border-color: var(--color-primary);
    background: rgba(3, 199, 90, 0.1);
    transform: translateY(-4px);
}

.letter-tile.selected {
    background: var(--gradient-primary);
    color: #000;
    border-color: var(--color-primary);
    transform: scale(0.95);
}

.letter-tile.correct {
    background: var(--color-success);
    border-color: var(--color-success);
    animation: pulse 0.3s ease;
}

.letter-tile.wrong {
    background: var(--color-error);
    border-color: var(--color-error);
    animation: shake 0.3s ease;
}

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

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

/* Answer Input */
.answer-display {
    display: flex;
    justify-content: center;
    gap: var(--space-xs);
    margin-bottom: var(--space-lg);
    min-height: 64px;
    flex-wrap: wrap;
}

.answer-slot {
    width: 48px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.05);
    border: 2px dashed rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-xl);
    font-weight: 700;
    text-transform: uppercase;
    transition: var(--transition-normal);
}

.answer-slot.filled {
    background: var(--color-bg-card);
    border: 2px solid var(--color-primary);
    color: var(--color-primary);
}

/* Game Controls */
.game-controls {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    margin-top: var(--space-xl);
}

/* Timer */
.timer-bar {
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-full);
    overflow: hidden;
    margin-bottom: var(--space-lg);
}

.timer-progress {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: width 0.1s linear;
}

.timer-progress.warning {
    background: var(--color-warning);
}

.timer-progress.danger {
    background: var(--color-error);
}

/* Hint Section */
.hint-section {
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    margin-top: var(--space-lg);
    text-align: center;
}

.hint-text {
    color: var(--color-text-secondary);
    font-size: var(--font-size-sm);
}

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

/* ========================================
   Ranking Section
======================================== */
.ranking-section {
    padding: var(--space-3xl) 0;
}

.ranking-tabs {
    display: flex;
    gap: var(--space-sm);
    justify-content: center;
    margin-bottom: var(--space-xl);
}

.ranking-tab {
    padding: var(--space-sm) var(--space-lg);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-tertiary);
    background: rgba(255, 255, 255, 0.05);
    cursor: pointer;
    transition: var(--transition-normal);
}

.ranking-tab:hover,
.ranking-tab.active {
    color: var(--color-text-primary);
    background: var(--color-primary);
}

.ranking-list {
    max-width: 600px;
    margin: 0 auto;
}

.ranking-item {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: var(--color-bg-card);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-sm);
    transition: var(--transition-normal);
}

.ranking-item:hover {
    background: var(--color-bg-card-hover);
}

.ranking-item.top-3 {
    border: 1px solid rgba(255, 215, 0, 0.3);
}

.ranking-position {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: var(--font-size-lg);
}

.ranking-position.gold {
    background: linear-gradient(135deg, #FFD700, #FFA500);
    color: #000;
}

.ranking-position.silver {
    background: linear-gradient(135deg, #C0C0C0, #A8A8A8);
    color: #000;
}

.ranking-position.bronze {
    background: linear-gradient(135deg, #CD7F32, #B87333);
    color: #fff;
}

.ranking-info {
    flex: 1;
}

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

.ranking-stats {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.ranking-score {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-primary);
}

/* ========================================
   Achievement Section
======================================== */
.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--space-md);
}

.achievement-card {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-lg);
    background: var(--color-bg-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-normal);
}

.achievement-card.locked {
    opacity: 0.5;
    filter: grayscale(1);
}

.achievement-card.unlocked {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-glow);
}

.achievement-icon {
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-cosmic);
    border-radius: var(--radius-md);
    font-size: 28px;
}

.achievement-info {
    flex: 1;
}

.achievement-name {
    font-weight: 600;
    margin-bottom: var(--space-xs);
}

.achievement-desc {
    font-size: var(--font-size-sm);
    color: var(--color-text-tertiary);
}

.achievement-points {
    font-size: var(--font-size-sm);
    color: var(--color-primary);
    font-weight: 600;
}

/* ========================================
   Difficulty Selection
======================================== */
.difficulty-selector {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    margin-bottom: var(--space-xl);
}

.difficulty-btn {
    padding: var(--space-md) var(--space-xl);
    border-radius: var(--radius-full);
    font-weight: 600;
    background: var(--color-bg-card);
    color: var(--color-text-secondary);
    border: 2px solid transparent;
    transition: var(--transition-normal);
}

.difficulty-btn:hover {
    background: var(--color-bg-card-hover);
}

.difficulty-btn.easy.active {
    background: rgba(0, 230, 118, 0.2);
    border-color: #00e676;
    color: #00e676;
}

.difficulty-btn.medium.active {
    background: rgba(255, 165, 2, 0.2);
    border-color: #ffa502;
    color: #ffa502;
}

.difficulty-btn.hard.active {
    background: rgba(255, 71, 87, 0.2);
    border-color: #ff4757;
    color: #ff4757;
}

/* ========================================
   Modal
======================================== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-normal);
}

.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--color-bg-card);
    border-radius: var(--radius-xl);
    padding: var(--space-2xl);
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    transform: scale(0.9);
    transition: var(--transition-normal);
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.modal-close {
    position: absolute;
    top: var(--space-md);
    right: var(--space-md);
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.1);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: var(--transition-normal);
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.2);
    color: var(--color-text-primary);
}

.modal-title {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--space-lg);
    text-align: center;
}

/* ========================================
   Game Result Modal
======================================== */
.result-modal {
    text-align: center;
}

.result-icon {
    width: 100px;
    height: 100px;
    margin: 0 auto var(--space-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
    font-size: 48px;
}

.result-icon.success {
    background: rgba(3, 199, 90, 0.2);
    animation: successPulse 2s ease infinite;
}

@keyframes successPulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(3, 199, 90, 0.4); }
    50% { box-shadow: 0 0 0 20px rgba(3, 199, 90, 0); }
}

.result-score {
    font-size: var(--font-size-5xl);
    font-weight: 900;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-md);
}

.result-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-md);
    margin: var(--space-xl) 0;
    padding: var(--space-lg);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
}

.result-stat {
    text-align: center;
}

.result-stat-value {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--color-text-primary);
}

.result-stat-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-tertiary);
    text-transform: uppercase;
}

.result-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
}

/* ========================================
   Nickname Input
======================================== */
.nickname-input-container {
    display: flex;
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
}

.nickname-input {
    flex: 1;
    padding: var(--space-md) var(--space-lg);
    border-radius: var(--radius-full);
    border: 2px solid rgba(255, 255, 255, 0.1);
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
    font-size: var(--font-size-md);
    transition: var(--transition-normal);
}

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

.nickname-input::placeholder {
    color: var(--color-text-tertiary);
}

/* ========================================
   Section Headers
======================================== */
.section-header {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.section-title {
    font-size: var(--font-size-3xl);
    margin-bottom: var(--space-md);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ========================================
   Footer
======================================== */
.site-footer {
    background: var(--color-bg-secondary);
    padding: var(--space-3xl) 0 var(--space-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

.footer-section h4 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--space-md);
    color: var(--color-text-primary);
}

.footer-section ul li {
    margin-bottom: var(--space-sm);
}

.footer-section a {
    color: var(--color-text-tertiary);
    font-size: var(--font-size-sm);
    transition: var(--transition-normal);
}

.footer-section a:hover {
    color: var(--color-primary);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--space-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    color: var(--color-text-tertiary);
    font-size: var(--font-size-sm);
}

/* ========================================
   Toast Notifications
======================================== */
.toast-container {
    position: fixed;
    bottom: var(--space-xl);
    right: var(--space-xl);
    z-index: var(--z-toast);
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.toast {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-md) var(--space-lg);
    background: var(--color-bg-card);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    animation: slideIn 0.3s ease;
    min-width: 300px;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

.toast.success { border-left: 4px solid var(--color-success); }
.toast.error { border-left: 4px solid var(--color-error); }
.toast.warning { border-left: 4px solid var(--color-warning); }
.toast.info { border-left: 4px solid var(--color-info); }

.toast-icon {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-full);
}

.toast.success .toast-icon { background: rgba(3, 199, 90, 0.2); color: var(--color-success); }
.toast.error .toast-icon { background: rgba(255, 71, 87, 0.2); color: var(--color-error); }

.toast-message {
    flex: 1;
    font-size: var(--font-size-sm);
}

/* ========================================
   Loading States
======================================== */
.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-top-color: var(--color-primary);
    border-radius: var(--radius-full);
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-overlay {
    position: fixed;
    inset: 0;
    background: var(--color-bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: var(--z-overlay);
}

.loading-logo {
    font-size: var(--font-size-3xl);
    font-weight: 800;
    margin-bottom: var(--space-lg);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ========================================
   Slider Section
======================================== */
.slider-section {
    position: relative;
    padding: var(--space-2xl) 0;
    overflow: hidden;
}

.slider-container {
    position: relative;
    max-width: 1200px;
    margin: 0 auto;
}

.slider-track {
    display: flex;
    transition: transform 0.5s ease;
}

.slide {
    flex: 0 0 100%;
    padding: 0 var(--space-md);
}

.slide-content {
    background: var(--gradient-card);
    border-radius: var(--radius-xl);
    padding: var(--space-3xl);
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.slider-nav {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-full);
    color: var(--color-text-primary);
    cursor: pointer;
    transition: var(--transition-normal);
    z-index: 10;
}

.slider-nav:hover {
    background: var(--color-primary);
    color: #000;
}

.slider-nav.prev { left: var(--space-md); }
.slider-nav.next { right: var(--space-md); }

.slider-dots {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
    margin-top: var(--space-lg);
}

.slider-dot {
    width: 8px;
    height: 8px;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.2);
    cursor: pointer;
    transition: var(--transition-normal);
}

.slider-dot.active {
    width: 24px;
    background: var(--color-primary);
}

/* ========================================
   Page Specific Styles
======================================== */
.page-section {
    padding: var(--space-3xl) 0;
}

.page-header {
    text-align: center;
    padding: var(--space-3xl) 0;
    background: var(--gradient-card);
    margin-bottom: var(--space-2xl);
}

.page-title {
    font-size: var(--font-size-4xl);
    margin-bottom: var(--space-md);
}

.page-description {
    font-size: var(--font-size-lg);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ========================================
   Form Styles
======================================== */
.form-group {
    margin-bottom: var(--space-lg);
}

.form-label {
    display: block;
    font-size: var(--font-size-sm);
    font-weight: 500;
    margin-bottom: var(--space-sm);
    color: var(--color-text-secondary);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: var(--space-md);
    border-radius: var(--radius-md);
    border: 2px solid rgba(255, 255, 255, 0.1);
    background: var(--color-bg-secondary);
    color: var(--color-text-primary);
    font-size: var(--font-size-md);
    transition: var(--transition-normal);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-primary);
}

.form-textarea {
    min-height: 150px;
    resize: vertical;
}

/* ========================================
   Grid Layouts
======================================== */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-lg); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-lg); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-lg); }

/* ========================================
   Utility Classes
======================================== */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-primary { color: var(--color-primary); }
.text-secondary { color: var(--color-text-secondary); }
.text-muted { color: var(--color-text-tertiary); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--space-sm); }
.mt-2 { margin-top: var(--space-md); }
.mt-3 { margin-top: var(--space-lg); }
.mt-4 { margin-top: var(--space-xl); }
.mt-5 { margin-top: var(--space-2xl); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--space-sm); }
.mb-2 { margin-bottom: var(--space-md); }
.mb-3 { margin-bottom: var(--space-lg); }
.mb-4 { margin-bottom: var(--space-xl); }
.mb-5 { margin-bottom: var(--space-2xl); }

.py-1 { padding-top: var(--space-sm); padding-bottom: var(--space-sm); }
.py-2 { padding-top: var(--space-md); padding-bottom: var(--space-md); }
.py-3 { padding-top: var(--space-lg); padding-bottom: var(--space-lg); }
.py-4 { padding-top: var(--space-xl); padding-bottom: var(--space-xl); }
.py-5 { padding-top: var(--space-2xl); padding-bottom: var(--space-2xl); }

.flex { display: flex; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-between { display: flex; align-items: center; justify-content: space-between; }
.flex-wrap { flex-wrap: wrap; }
.gap-1 { gap: var(--space-sm); }
.gap-2 { gap: var(--space-md); }
.gap-3 { gap: var(--space-lg); }

/* ========================================
   Responsive Styles
======================================== */
@media (max-width: 1024px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    :root {
        --font-size-4xl: 32px;
        --font-size-3xl: 26px;
        --font-size-2xl: 22px;
    }

    .main-nav {
        display: none;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .header-inner {
        padding: 0 var(--space-md);
    }

    .hero-section {
        padding: var(--space-2xl) 0;
        min-height: auto;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

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

    .game-card {
        padding: var(--space-lg);
    }

    .letter-tile {
        width: 44px;
        height: 52px;
        font-size: var(--font-size-xl);
    }

    .answer-slot {
        width: 40px;
        height: 48px;
        font-size: var(--font-size-lg);
    }

    .game-stats {
        gap: var(--space-md);
    }

    .stat-value {
        font-size: var(--font-size-xl);
    }

    .difficulty-selector {
        flex-wrap: wrap;
    }

    .difficulty-btn {
        padding: var(--space-sm) var(--space-md);
        font-size: var(--font-size-sm);
    }

    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .toast-container {
        left: var(--space-md);
        right: var(--space-md);
        bottom: var(--space-md);
    }

    .toast {
        min-width: auto;
    }

    .result-stats {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .scrambled-word {
        gap: var(--space-xs);
    }

    .letter-tile {
        width: 38px;
        height: 46px;
        font-size: var(--font-size-lg);
    }

    .answer-slot {
        width: 34px;
        height: 42px;
        font-size: var(--font-size-md);
    }

    .btn-lg {
        padding: var(--space-md) var(--space-lg);
        font-size: var(--font-size-md);
    }
}

/* ========================================
   Animations
======================================== */
.fade-in {
    animation: fadeIn 0.5s ease forwards;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.slide-up {
    animation: slideUp 0.5s ease forwards;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(40px); }
    to { opacity: 1; transform: translateY(0); }
}

.scale-in {
    animation: scaleIn 0.3s ease forwards;
}

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.8); }
    to { opacity: 1; transform: scale(1); }
}

/* Staggered animations */
.stagger-1 { animation-delay: 0.1s; }
.stagger-2 { animation-delay: 0.2s; }
.stagger-3 { animation-delay: 0.3s; }
.stagger-4 { animation-delay: 0.4s; }
.stagger-5 { animation-delay: 0.5s; }

/* ========================================
   Print Styles
======================================== */
@media print {
    .site-header,
    .site-footer,
    .mobile-nav,
    .toast-container {
        display: none;
    }

    .site-main {
        padding-top: 0;
    }

    body {
        background: #fff;
        color: #000;
    }
}