/* ===========================
   Regex Debugger Visual — Premium Styles
   =========================== */

:root {
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 6px;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.12);
  --shadow-lg: 0 8px 32px rgba(0,0,0,0.18);
}

[data-theme="dark"] {
  --bg-primary: #0B0D13;
  --bg-secondary: #12151E;
  --bg-tertiary: #1A1E2E;
  --bg-card: rgba(26, 30, 46, 0.7);
  --bg-hover: rgba(108, 99, 255, 0.08);
  --border: rgba(255,255,255,0.06);
  --border-active: rgba(108, 99, 255, 0.4);
  --text-primary: #F0F0F5;
  --text-secondary: #8B8FA3;
  --text-muted: #555977;
  --accent: #6C63FF;
  --accent-light: #A78BFA;
  --accent-glow: rgba(108, 99, 255, 0.15);
  --success: #34D399;
  --warning: #FBBF24;
  --error: #F87171;
  --info: #38BDF8;
  --glass: rgba(26, 30, 46, 0.6);
  --glass-border: rgba(255,255,255,0.08);
  --match-bg: rgba(108, 99, 255, 0.2);
  --match-border: rgba(108, 99, 255, 0.5);
  --group1: #6C63FF;
  --group2: #38BDF8;
  --group3: #34D399;
  --group4: #FBBF24;
  --group5: #F87171;
}

[data-theme="light"] {
  --bg-primary: #F8F9FC;
  --bg-secondary: #FFFFFF;
  --bg-tertiary: #F0F1F5;
  --bg-card: rgba(255, 255, 255, 0.8);
  --bg-hover: rgba(108, 99, 255, 0.06);
  --border: rgba(0,0,0,0.08);
  --border-active: rgba(108, 99, 255, 0.4);
  --text-primary: #1A1D2E;
  --text-secondary: #64687C;
  --text-muted: #9CA0B4;
  --accent: #6C63FF;
  --accent-light: #8B83FF;
  --accent-glow: rgba(108, 99, 255, 0.1);
  --success: #059669;
  --warning: #D97706;
  --error: #DC2626;
  --info: #0284C7;
  --glass: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(0,0,0,0.06);
  --match-bg: rgba(108, 99, 255, 0.12);
  --match-border: rgba(108, 99, 255, 0.4);
  --group1: #6C63FF;
  --group2: #0284C7;
  --group3: #059669;
  --group4: #D97706;
  --group5: #DC2626;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-font-smoothing: antialiased; }
body { font-family: var(--font); background: var(--bg-primary); color: var(--text-primary); min-height: 100vh; transition: background var(--transition), color var(--transition); line-height: 1.6; }

/* Header */
.header { position: sticky; top: 0; z-index: 100; background: var(--glass); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); border-bottom: 1px solid var(--glass-border); }
.header-content { max-width: 1100px; margin: 0 auto; padding: 0.75rem 1.5rem; display: flex; align-items: center; justify-content: space-between; }
.logo { display: flex; align-items: center; gap: 0.75rem; }
.logo-text { font-size: 1.125rem; font-weight: 700; letter-spacing: -0.02em; background: linear-gradient(135deg, var(--accent), var(--accent-light)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.header-actions { display: flex; gap: 0.5rem; }

/* Buttons */
.icon-btn { width: 36px; height: 36px; border: 1px solid var(--border); border-radius: var(--radius-sm); background: var(--bg-card); color: var(--text-secondary); cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all var(--transition); }
.icon-btn:hover { background: var(--bg-hover); color: var(--accent); border-color: var(--border-active); }
.icon-btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.btn { display: inline-flex; align-items: center; gap: 0.375rem; padding: 0.4rem 0.875rem; border-radius: var(--radius-xs); font-family: var(--font); font-size: 0.8125rem; font-weight: 500; cursor: pointer; transition: all var(--transition); border: 1px solid var(--border); background: var(--bg-card); color: var(--text-secondary); }
.btn:hover { background: var(--bg-hover); color: var(--accent); border-color: var(--border-active); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn:disabled:hover { background: var(--bg-card); color: var(--text-secondary); border-color: var(--border); }
.btn-sm { padding: 0.3rem 0.625rem; font-size: 0.75rem; }
.btn-accent { background: var(--accent); color: white; border-color: var(--accent); }
.btn-accent:hover { background: var(--accent-light); border-color: var(--accent-light); color: white; }
.btn:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

[data-theme="dark"] .sun-icon { display: block; }
[data-theme="dark"] .moon-icon { display: none; }
[data-theme="light"] .sun-icon { display: none; }
[data-theme="light"] .moon-icon { display: block; }

/* Main */
.main { max-width: 1100px; margin: 0 auto; padding: 1.5rem; display: flex; flex-direction: column; gap: 1.5rem; }

/* Input Panel */
.input-panel { display: flex; flex-direction: column; gap: 1rem; padding: 1.25rem; background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); backdrop-filter: blur(12px); }

.input-group { display: flex; flex-direction: column; gap: 0.5rem; }
.input-label { display: flex; align-items: center; gap: 0.5rem; font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); }

.regex-input-wrapper { display: flex; align-items: center; gap: 0; background: var(--bg-secondary); border: 1px solid var(--border); border-radius: var(--radius-sm); overflow: hidden; transition: border-color var(--transition); }
.regex-input-wrapper:focus-within { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }
.regex-delim { padding: 0.625rem 0.5rem; font-family: var(--font-mono); font-size: 1.125rem; color: var(--text-muted); user-select: none; }
.regex-field { flex: 1; background: none; border: none; outline: none; font-family: var(--font-mono); font-size: 0.9375rem; color: var(--text-primary); padding: 0.625rem 0; }
.flags-field { width: 48px; background: none; border: none; border-left: 1px solid var(--border); outline: none; font-family: var(--font-mono); font-size: 0.9375rem; color: var(--accent); padding: 0.625rem 0.5rem; text-align: center; }

.test-field { width: 100%; background: var(--bg-secondary); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 0.75rem; font-family: var(--font-mono); font-size: 0.875rem; color: var(--text-primary); resize: vertical; min-height: 80px; transition: border-color var(--transition); outline: none; line-height: 1.6; }
.test-field:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-glow); }

/* Presets */
.presets { display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap; }
.presets-label { font-size: 0.75rem; color: var(--text-muted); font-weight: 500; }
.preset-btn { padding: 0.25rem 0.625rem; font-size: 0.6875rem; font-weight: 500; font-family: var(--font); border: 1px solid var(--border); border-radius: 999px; background: var(--bg-secondary); color: var(--text-secondary); cursor: pointer; transition: all var(--transition); }
.preset-btn:hover { border-color: var(--accent); color: var(--accent); background: var(--bg-hover); }

/* Results */
.results-panel { display: flex; flex-direction: column; gap: 1rem; }
.hidden { display: none !important; }

/* Error banner */
.error-banner { display: flex; align-items: center; gap: 0.625rem; padding: 0.75rem 1rem; background: rgba(248, 113, 113, 0.1); border: 1px solid rgba(248, 113, 113, 0.3); border-radius: var(--radius-sm); color: var(--error); font-size: 0.8125rem; font-family: var(--font-mono); }

/* Stats bar */
.stats-bar { display: flex; gap: 0.75rem; flex-wrap: wrap; }
.stat { flex: 1; min-width: 100px; padding: 0.875rem 1rem; background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius-sm); backdrop-filter: blur(12px); text-align: center; }
.stat-value { display: block; font-size: 1.25rem; font-weight: 700; color: var(--accent); font-variant-numeric: tabular-nums; }
.stat-label { font-size: 0.6875rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--text-muted); }

/* Result sections */
.result-section { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); backdrop-filter: blur(12px); overflow: hidden; }
.section-title { display: flex; align-items: center; gap: 0.5rem; font-size: 0.75rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-muted); padding: 0.875rem 1rem; border-bottom: 1px solid var(--border); }

/* Highlight view */
.highlight-view { padding: 1rem; font-family: var(--font-mono); font-size: 0.875rem; line-height: 1.8; white-space: pre-wrap; word-break: break-all; color: var(--text-primary); min-height: 60px; }
.highlight-view .match { background: var(--match-bg); border: 1px solid var(--match-border); border-radius: 3px; padding: 0.125rem 0.25rem; position: relative; cursor: pointer; transition: background var(--transition); }
.highlight-view .match:hover { background: rgba(108, 99, 255, 0.35); }
.highlight-view .match .match-index { position: absolute; top: -18px; left: 0; font-size: 0.5625rem; color: var(--accent); font-weight: 600; letter-spacing: 0.04em; pointer-events: none; }
.highlight-view .group { border-bottom: 2px solid; padding-bottom: 1px; }
.highlight-view .group-1 { border-color: var(--group1); }
.highlight-view .group-2 { border-color: var(--group2); }
.highlight-view .group-3 { border-color: var(--group3); }
.highlight-view .group-4 { border-color: var(--group4); }
.highlight-view .group-5 { border-color: var(--group5); }

.placeholder-text { color: var(--text-muted); font-size: 0.8125rem; font-family: var(--font); font-style: italic; }

/* Match details */
.match-details { padding: 0.5rem; max-height: 300px; overflow-y: auto; }
.match-card { padding: 0.75rem; margin: 0.375rem 0.5rem; background: var(--bg-secondary); border: 1px solid var(--border); border-radius: var(--radius-sm); transition: border-color var(--transition); }
.match-card:hover { border-color: var(--border-active); }
.match-card-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 0.5rem; }
.match-number { font-size: 0.6875rem; font-weight: 700; color: var(--accent); text-transform: uppercase; letter-spacing: 0.06em; }
.match-position { font-size: 0.6875rem; color: var(--text-muted); font-family: var(--font-mono); }
.match-value { font-family: var(--font-mono); font-size: 0.8125rem; color: var(--text-primary); padding: 0.375rem 0.5rem; background: var(--bg-tertiary); border-radius: 4px; margin-bottom: 0.375rem; word-break: break-all; }
.group-list { display: flex; flex-direction: column; gap: 0.25rem; margin-top: 0.375rem; }
.group-item { display: flex; align-items: center; gap: 0.5rem; font-size: 0.75rem; }
.group-badge { display: inline-flex; align-items: center; justify-content: center; width: 20px; height: 20px; border-radius: 50%; font-size: 0.625rem; font-weight: 700; color: white; flex-shrink: 0; }
.group-badge-1 { background: var(--group1); }
.group-badge-2 { background: var(--group2); }
.group-badge-3 { background: var(--group3); }
.group-badge-4 { background: var(--group4); }
.group-badge-5 { background: var(--group5); }
.group-value { font-family: var(--font-mono); color: var(--text-primary); }

/* Step view */
.step-controls { display: flex; align-items: center; gap: 0.75rem; padding: 0.75rem 1rem; border-bottom: 1px solid var(--border); flex-wrap: wrap; }
.step-indicator { font-size: 0.75rem; color: var(--text-muted); font-variant-numeric: tabular-nums; min-width: 80px; text-align: center; }

.step-view { padding: 1rem; min-height: 80px; }
.step-view .step-content { display: flex; flex-direction: column; gap: 0.75rem; }
.step-string { font-family: var(--font-mono); font-size: 0.9375rem; line-height: 1.8; white-space: pre-wrap; word-break: break-all; }
.step-string .current-char { background: var(--warning); color: #1A1D2E; padding: 0.125rem 0.25rem; border-radius: 3px; font-weight: 600; }
.step-string .matched-char { background: var(--match-bg); border: 1px solid var(--match-border); border-radius: 3px; padding: 0.125rem 0.125rem; }
.step-desc { font-size: 0.8125rem; color: var(--text-secondary); padding: 0.5rem 0.75rem; background: var(--bg-secondary); border-radius: var(--radius-xs); border-left: 3px solid var(--accent); }

/* Explanation */
.explanation { padding: 1rem; }
.explanation .token-list { display: flex; flex-direction: column; gap: 0.5rem; }
.token-item { display: flex; align-items: flex-start; gap: 0.75rem; padding: 0.5rem 0.625rem; border-radius: var(--radius-xs); transition: background var(--transition); }
.token-item:hover { background: var(--bg-hover); }
.token-pattern { font-family: var(--font-mono); font-size: 0.8125rem; font-weight: 600; color: var(--accent); min-width: 80px; flex-shrink: 0; padding: 0.25rem 0.5rem; background: var(--bg-secondary); border-radius: 4px; text-align: center; }
.token-desc { font-size: 0.8125rem; color: var(--text-secondary); line-height: 1.5; }

/* Toast */
.toast-container { position: fixed; bottom: 1.5rem; right: 1.5rem; z-index: 2000; display: flex; flex-direction: column; gap: 0.5rem; }
.toast { display: flex; align-items: center; gap: 0.75rem; padding: 0.75rem 1rem; border-radius: var(--radius-sm); background: var(--bg-secondary); border: 1px solid var(--border); box-shadow: var(--shadow-lg); font-size: 0.8125rem; max-width: 320px; animation: toastIn 0.3s ease, toastOut 0.3s ease 2.7s forwards; }
.toast.success { border-left: 3px solid var(--success); }
.toast.info { border-left: 3px solid var(--info); }

@keyframes toastIn { from { opacity: 0; transform: translateX(20px); } to { opacity: 1; transform: translateX(0); } }
@keyframes toastOut { from { opacity: 1; } to { opacity: 0; transform: translateX(20px); } }

/* Responsive */
@media (max-width: 768px) {
  .main { padding: 1rem; }
  .stats-bar { gap: 0.5rem; }
  .stat { min-width: 70px; padding: 0.625rem 0.5rem; }
  .stat-value { font-size: 1rem; }
  .step-controls { gap: 0.5rem; }
}

@media (max-width: 480px) {
  .header-content { padding: 0.75rem 1rem; }
  .logo-text { font-size: 0.9375rem; }
  .regex-input-wrapper { flex-wrap: wrap; }
  .flags-field { border-left: none; border-top: 1px solid var(--border); width: 100%; text-align: left; }
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--text-muted); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-secondary); }