* { margin: 0; padding: 0; box-sizing: border-box; }
:root { --primary: #ef4444; --primary-dark: #dc2626; --bg: #0f172a; --bg-card: #1e293b; --bg-input: #334155; --text: #f1f5f9; --text-muted: #94a3b8; --border: #475569; }
body { font-family: -apple-system, sans-serif; background: var(--bg); color: var(--text); min-height: 100vh; line-height: 1.6; }
.container { max-width: 600px; margin: 0 auto; padding: 2rem 1rem; }
header { text-align: center; margin-bottom: 2rem; }
h1 { font-size: 2.5rem; margin-bottom: 0.5rem; background: linear-gradient(135deg, var(--primary), #f97316); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.subtitle { color: var(--text-muted); margin-bottom: 1rem; }
.badges { display: flex; gap: 0.5rem; justify-content: center; flex-wrap: wrap; }
.badge { padding: 0.25rem 0.75rem; border-radius: 999px; font-size: 0.85rem; }
.badge-green { background: rgba(16, 185, 129, 0.2); color: #34d399; }
.badge-blue { background: rgba(59, 130, 246, 0.2); color: #60a5fa; }
.badge-purple { background: rgba(139, 92, 246, 0.2); color: #a78bfa; }
.timer-card { background: var(--bg-card); border-radius: 1rem; padding: 2rem; margin-bottom: 2rem; border: 1px solid var(--border); text-align: center; }
.mode-tabs { display: flex; gap: 0.5rem; justify-content: center; margin-bottom: 2rem; }
.mode-tab { padding: 0.75rem 1.5rem; border: 2px solid var(--border); border-radius: 0.5rem; background: transparent; color: var(--text); cursor: pointer; font-weight: 500; transition: all 0.2s; }
.mode-tab.active { background: var(--primary); border-color: var(--primary); }
.mode-tab:hover:not(.active) { border-color: var(--primary); }
.timer-display { font-size: 6rem; font-weight: 700; font-family: 'Monaco', monospace; margin-bottom: 2rem; letter-spacing: -0.05em; }
.timer-controls { display: flex; gap: 1rem; justify-content: center; margin-bottom: 1.5rem; }
.btn-primary { padding: 1rem 2rem; font-size: 1.1rem; font-weight: 600; background: var(--primary); color: white; border: none; border-radius: 0.5rem; cursor: pointer; min-width: 140px; }
.btn-secondary { padding: 1rem 2rem; font-size: 1.1rem; font-weight: 600; background: transparent; color: var(--text); border: 2px solid var(--border); border-radius: 0.5rem; cursor: pointer; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary:hover { border-color: var(--text); }
.session-info { color: var(--text-muted); margin-bottom: 2rem; }
.session-info strong { color: var(--primary); font-size: 1.25rem; }
.settings-section { border-top: 1px solid var(--border); padding-top: 1.5rem; }
.settings-section h4 { margin-bottom: 1rem; color: var(--text-muted); }
.settings-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.setting label { display: block; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 0.25rem; }
.setting input { width: 100%; padding: 0.5rem; border: 2px solid var(--border); border-radius: 0.5rem; background: var(--bg-input); color: var(--text); text-align: center; font-size: 1rem; }
.features { margin-bottom: 2rem; }
.features h2 { text-align: center; margin-bottom: 1.5rem; }
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 1rem; }
.feature { background: var(--bg-card); padding: 1.25rem; border-radius: 1rem; border: 1px solid var(--border); text-align: center; }
.feature-icon { font-size: 1.5rem; display: block; margin-bottom: 0.5rem; }
.feature h3 { font-size: 0.95rem; margin-bottom: 0.25rem; }
.feature p { color: var(--text-muted); font-size: 0.8rem; }
.faq { margin-bottom: 2rem; }
.faq h2 { text-align: center; margin-bottom: 1.5rem; }
.faq-category { margin-bottom: 1.5rem; }
.faq-category-title { font-size: 1.1rem; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--primary); color: var(--primary); }
.faq-item { background: var(--bg-card); padding: 1.25rem; border-radius: 0.75rem; margin-bottom: 0.75rem; border: 1px solid var(--border); }
.faq-item h4 { margin-bottom: 0.5rem; }
.faq-item p { color: var(--text-muted); font-size: 0.9rem; }
footer { text-align: center; padding: 2rem 0; border-top: 1px solid var(--border); color: var(--text-muted); }
@media (max-width: 500px) { .timer-display { font-size: 4rem; } .settings-grid { grid-template-columns: 1fr; } h1 { font-size: 2rem; } }