/* FitMatrix AI 24h - Design System */
:root {
    --bg-dark: #090d16;
    --card-bg: #131b2e;
    --accent-cyan: #06b6d4;
    --accent-gold: #fee500;
    --accent-red: #ef4444;
    --text-light: #f8fafc;
    --text-muted: #94a3b8;
    --border-color: rgba(255, 255, 255, 0.1);
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Outfit', 'Noto Sans KR', sans-serif; }
body { background-color: var(--bg-dark); color: var(--text-light); min-height: 100vh; display: flex; flex-direction: column; }

/* HEADER */
.app-header { background: #0f172a; border-bottom: 1px solid var(--border-color); padding: 16px 24px; }
.header-container { max-width: 1280px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.status-badge { background: rgba(6, 182, 212, 0.2); color: var(--accent-cyan); font-size: 0.75rem; font-weight: 800; padding: 4px 8px; border-radius: 6px; border: 1px solid var(--accent-cyan); }
.logo-area h1 { font-size: 1.5rem; font-weight: 900; color: #fff; margin-top: 4px; }
.logo-area p { font-size: 0.85rem; color: var(--text-muted); }
.header-controls { display: flex; gap: 12px; align-items: center; }
.country-pill select { background: #1e293b; color: #fff; border: 1px solid var(--border-color); padding: 6px 10px; border-radius: 8px; font-weight: 700; cursor: pointer; }
.country-pill select option { background-color: #0f172a !important; color: #ffffff !important; }
.app-store-btn { background: linear-gradient(135deg, #06b6d4, #3b82f6); color: #fff; text-decoration: none; padding: 8px 14px; border-radius: 8px; font-weight: 700; font-size: 0.85rem; }

/* NAVIGATION TABS */
.app-nav { background: #0f172a; border-bottom: 1px solid var(--border-color); display: flex; gap: 8px; padding: 10px 24px; overflow-x: auto; max-width: 1280px; margin: 0 auto; width: 100%; }
.nav-tab { background: transparent; color: var(--text-muted); border: 1px solid transparent; padding: 10px 16px; border-radius: 8px; font-weight: 700; font-size: 0.9rem; cursor: pointer; white-space: nowrap; transition: 0.2s; }
.nav-tab:hover { color: #fff; background: rgba(255, 255, 255, 0.05); }
.nav-tab.active { background: rgba(6, 182, 212, 0.15); color: var(--accent-cyan); border-color: var(--accent-cyan); }

/* MAIN CONTENT & PANELS */
.main-content { max-width: 1280px; margin: 24px auto; padding: 0 24px; flex: 1; width: 100%; }
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* TAB 1: WORKOUT DASHBOARD */
.workout-dashboard { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
@media (max-width: 900px) { .workout-dashboard { grid-template-columns: 1fr; } }

.workout-logger-panel, .muscle-heatmap-panel, .music-section-container, .swap-section-container, .chart-section-container, .timer-section-container {
    background: var(--card-bg); border: 1px solid var(--border-color); border-radius: 16px; padding: 24px;
}

h3 { font-size: 1.25rem; font-weight: 800; color: #fff; margin-bottom: 12px; }
.panel-sub { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 20px; }

.exercise-selector-box { margin-bottom: 20px; }
.exercise-selector-box label { display: block; font-size: 0.9rem; font-weight: 700; color: var(--accent-gold); margin-bottom: 6px; }
.exercise-selector-box select { width: 100%; background: #0f172a; color: #fff; border: 1px solid var(--border-color); padding: 12px; border-radius: 10px; font-size: 1rem; font-weight: 700; }
.exercise-selector-box select option { background-color: #0f172a !important; color: #ffffff !important; }

.quick-set-inputs { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 20px; }
.input-card { background: #0f172a; border: 1px solid var(--border-color); border-radius: 12px; padding: 14px; text-align: center; }
.input-card label { display: block; font-size: 0.8rem; color: var(--text-muted); margin-bottom: 4px; }
.input-card input { width: 100%; background: transparent; border: none; color: #fff; font-size: 1.8rem; font-weight: 900; text-align: center; margin-bottom: 8px; }
.step-btns { display: flex; gap: 6px; justify-content: center; }
.step-btns button { background: #1e293b; color: #fff; border: none; padding: 4px 12px; border-radius: 6px; font-weight: 700; cursor: pointer; }

.btn-primary-big { width: 100%; background: linear-gradient(135deg, #06b6d4, #3b82f6); color: #fff; border: none; padding: 16px; border-radius: 12px; font-size: 1.05rem; font-weight: 800; cursor: pointer; box-shadow: 0 4px 14px rgba(6, 182, 212, 0.4); }
.btn-primary-big:hover { opacity: 0.9; }

.today-volume-card { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 12px; background: #0f172a; border: 1px solid var(--border-color); border-radius: 12px; padding: 16px; margin-top: 20px; }
.vol-stat { text-align: center; }
.vol-stat span { display: block; font-size: 0.75rem; color: var(--text-muted); margin-bottom: 4px; }
.vol-stat strong { font-size: 1.1rem; color: var(--accent-gold); font-weight: 800; }

/* CANVAS VIEWPORT */
.canvas-viewport { text-align: center; margin-bottom: 20px; background: #0f172a; border-radius: 12px; padding: 12px; }
#muscle-canvas { max-width: 100%; height: auto; border-radius: 8px; }

.muscle-stats-grid { display: flex; flex-direction: column; gap: 10px; }
.m-bar-item { display: flex; align-items: center; gap: 12px; font-size: 0.85rem; }
.m-bar-item span { width: 120px; color: var(--text-muted); font-weight: 600; }
.progress-track { flex: 1; background: #0f172a; height: 10px; border-radius: 6px; overflow: hidden; }
.progress-fill { height: 100%; background: linear-gradient(90deg, #06b6d4, #ef4444); transition: width 0.3s; }
.m-bar-item strong { width: 45px; text-align: right; color: var(--accent-cyan); font-weight: 800; }

/* MUSIC PLAYER SECTION */
.music-genre-chips { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 20px; }
.m-chip { background: #0f172a; color: var(--text-muted); border: 1px solid var(--border-color); padding: 10px 16px; border-radius: 10px; font-size: 0.9rem; font-weight: 700; cursor: pointer; }
.m-chip.active { background: rgba(254, 229, 0, 0.15); color: var(--accent-gold); border-color: var(--accent-gold); }

.youtube-player-card { background: #0f172a; border: 1px solid var(--border-color); border-radius: 16px; padding: 20px; }
.player-header { margin-bottom: 16px; font-size: 1.1rem; font-weight: 800; color: var(--accent-gold); }
.iframe-responsive-container { border-radius: 12px; overflow: hidden; margin-bottom: 20px; box-shadow: 0 8px 24px rgba(0,0,0,0.5); }

.custom-url-box label { display: block; font-size: 0.85rem; color: var(--text-muted); margin-bottom: 8px; }
.url-input-group { display: flex; gap: 8px; }
.url-input-group input { flex: 1; background: #131b2e; color: #fff; border: 1px solid var(--border-color); padding: 10px 14px; border-radius: 8px; }
.url-input-group button { background: var(--accent-cyan); color: #fff; border: none; padding: 10px 18px; border-radius: 8px; font-weight: 700; cursor: pointer; }

/* FOOTER */
.app-footer { background: #0f172a; border-top: 1px solid var(--border-color); text-align: center; padding: 20px; font-size: 0.8rem; color: var(--text-muted); margin-top: auto; }