/* ============================================
   Regex Crossword — Styles
   Dark theme with indigo/cyan glassmorphism
   ============================================ */

:root {
    --primary: #6366F1;
    --primary-light: #818CF8;
    --accent: #22D3EE;
    --accent-light: #67E8F9;
    --bg: #0F172A;
    --bg-elevated: #1E293B;
    --bg-card: rgba(30, 41, 59, 0.8);
    --surface: #1E293B;
    --surface-hover: #334155;
    --text: #F1F5F9;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;
    --border: rgba(148, 163, 184, 0.12);
    --border-hover: rgba(99, 102, 241, 0.3);
    --success: #22C55E;
    --danger: #EF4444;
    --warning: #F59E0B;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 12px 48px rgba(0, 0, 0, 0.35);
    --transition: 0.2s ease;
    --font: 'Inter', system-ui, sans-serif;
    --mono: 'JetBrains Mono', monospace;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

.glass-card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

/* --- Header --- */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(15, 23, 42, 0.88);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
}

.header-inner {
    max-width: 900px;
    margin: 0 auto;
    padding: 0.625rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.625rem;
}

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

.logo h1 {
    font-size: 1.2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-stats {
    display: flex;
    gap: 1rem;
}

.stat {
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.stat span {
    font-weight: 700;
    color: var(--accent);
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.375rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--radius-sm);
    font-family: var(--font);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #fff;
    box-shadow: 0 2px 8px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    box-shadow: 0 4px 16px rgba(99, 102, 241, 0.5);
    transform: translateY(-1px);
}

.btn-accent {
    background: linear-gradient(135deg, var(--accent), var(--accent-light));
    color: #0F172A;
    box-shadow: 0 2px 8px rgba(34, 211, 238, 0.3);
}

.btn-accent:hover {
    box-shadow: 0 4px 16px rgba(34, 211, 238, 0.5);
    transform: translateY(-1px);
}

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

.btn-ghost:hover {
    background: var(--surface);
    color: var(--text);
}

.btn-sm {
    font-size: 0.8rem;
    padding: 0.375rem 0.75rem;
}

/* --- Main --- */
.main {
    max-width: 900px;
    margin: 0 auto;
    padding: 1.5rem;
}

.view {
    animation: fadeInView 0.3s ease;
}

/* --- Level Select --- */
.level-header {
    margin-bottom: 1.5rem;
}

.level-header h2 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.difficulty-tabs {
    display: flex;
    gap: 0.375rem;
    flex-wrap: wrap;
}

.tab {
    padding: 0.375rem 0.875rem;
    border: 1px solid var(--border);
    border-radius: 99px;
    background: transparent;
    color: var(--text-secondary);
    font-family: var(--font);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
}

.tab:hover {
    border-color: var(--primary);
    color: var(--text);
}

.tab.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.puzzle-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 0.75rem;
}

.puzzle-card {
    padding: 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-card);
    cursor: pointer;
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.puzzle-card:hover {
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.puzzle-card.solved {
    border-color: var(--success);
}

.puzzle-card.solved::after {
    content: '✅';
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    font-size: 0.85rem;
}

.puzzle-card {
    position: relative;
}

.puzzle-card-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.puzzle-number {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--primary-light);
}

.puzzle-card-title {
    font-size: 0.9rem;
    font-weight: 600;
    flex: 1;
}

.puzzle-card-meta {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.difficulty-badge {
    font-size: 0.65rem;
    font-weight: 600;
    padding: 0.125rem 0.5rem;
    border-radius: 99px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.difficulty-badge.beginner {
    background: rgba(34, 197, 94, 0.15);
    color: #4ADE80;
}

.difficulty-badge.easy {
    background: rgba(34, 211, 238, 0.15);
    color: var(--accent);
}

.difficulty-badge.medium {
    background: rgba(245, 158, 11, 0.15);
    color: #FBBF24;
}

.difficulty-badge.hard {
    background: rgba(239, 68, 68, 0.15);
    color: #F87171;
}

.difficulty-badge.expert {
    background: rgba(168, 85, 247, 0.15);
    color: #C084FC;
}

.puzzle-card-size {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.puzzle-card-score {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* --- Game View --- */
.game-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.game-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.puzzle-name {
    font-size: 1rem;
    font-weight: 600;
}

.game-timer {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.game-timer span {
    font-family: var(--mono);
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* --- Board --- */
.board-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.25rem;
    margin-bottom: 1.5rem;
}

.clues-top {
    display: flex;
    padding-left: 140px;
    gap: 2px;
}

.clue-top {
    width: 52px;
    text-align: center;
    font-family: var(--mono);
    font-size: 0.7rem;
    color: var(--accent);
    padding: 0.5rem 0.25rem;
    background: var(--surface);
    border-radius: 6px 6px 0 0;
    word-break: break-all;
    line-height: 1.2;
}

.clue-top.valid {
    color: var(--success);
}

.clue-top.invalid {
    color: var(--danger);
}

.board-and-rows {
    display: flex;
    gap: 2px;
}

.clues-left {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.clue-left {
    width: 138px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding-right: 0.625rem;
    font-family: var(--mono);
    font-size: 0.7rem;
    color: var(--accent);
    background: var(--surface);
    border-radius: 6px 0 0 6px;
    text-align: right;
    line-height: 1.2;
}

.clue-left.valid {
    color: var(--success);
}

.clue-left.invalid {
    color: var(--danger);
}

.grid-container {
    display: grid;
    gap: 2px;
}

.grid-cell {
    width: 52px;
    height: 52px;
    border: 2px solid var(--border);
    border-radius: 4px;
    background: var(--bg-elevated);
    font-family: var(--mono);
    font-size: 1.2rem;
    font-weight: 600;
    text-align: center;
    color: var(--text);
    text-transform: uppercase;
    transition: all var(--transition);
    caret-color: var(--accent);
}

.grid-cell:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.grid-cell.correct {
    border-color: var(--success);
    background: rgba(34, 197, 94, 0.08);
}

.grid-cell.incorrect {
    border-color: var(--danger);
    background: rgba(239, 68, 68, 0.08);
}

.grid-cell.hint {
    color: var(--accent);
    opacity: 0.7;
}

/* --- Validation Bar --- */
.validation-bar {
    text-align: center;
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    background: var(--surface);
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.validation-bar.success {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success);
    border: 1px solid rgba(34, 197, 94, 0.2);
}

.validation-bar.error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

/* --- Reference Panel --- */
.reference-panel {
    margin-top: 1rem;
    padding: 1rem;
}

.reference-panel summary {
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-secondary);
    list-style: none;
}

.reference-panel summary::-webkit-details-marker {
    display: none;
}

.reference-content {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 0.5rem;
    margin-top: 0.75rem;
}

.ref-item {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.ref-item code {
    font-family: var(--mono);
    color: var(--accent);
    font-size: 0.8rem;
    background: rgba(34, 211, 238, 0.08);
    padding: 0.125rem 0.375rem;
    border-radius: 4px;
    margin-right: 0.375rem;
}

/* --- Modal --- */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 200;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    padding: 2.5rem;
    text-align: center;
    max-width: 400px;
    width: 90%;
}

.win-icon {
    font-size: 3rem;
    margin-bottom: 0.75rem;
    animation: bounceIn 0.5s ease;
}

.win-stats {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    margin: 1.25rem 0;
}

.win-stat {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.win-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    font-weight: 600;
}

.win-value {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--accent);
}

.win-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
}

/* --- Toast --- */
.toast-container {
    position: fixed;
    bottom: 1.5rem;
    right: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 1000;
}

.toast {
    padding: 0.75rem 1.25rem;
    border-radius: var(--radius-sm);
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
    font-size: 0.85rem;
    animation: slideIn 0.3s ease, fadeOut 0.3s ease 2.7s forwards;
}

.toast.success {
    border-left: 3px solid var(--success);
}

.toast.error {
    border-left: 3px solid var(--danger);
}

@keyframes fadeInView {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounceIn {
    from {
        transform: scale(0);
    }

    50% {
        transform: scale(1.2);
    }

    to {
        transform: scale(1);
    }
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(100px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeOut {
    from {
        opacity: 1;
    }

    to {
        opacity: 0;
    }
}

@media (max-width: 640px) {
    .main {
        padding: 1rem;
    }

    .clue-left {
        width: 90px;
        font-size: 0.6rem;
    }

    .clue-top {
        font-size: 0.6rem;
    }

    .clues-top {
        padding-left: 92px;
    }

    .grid-cell {
        width: 40px;
        height: 40px;
        font-size: 1rem;
    }

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