:root {
    --primary: #4f46e5;
    --primary-light: #818cf8;
    --primary-dark: #3730a3;
    --secondary: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --radius: 16px;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.5;
    -webkit-tap-highlight-color: transparent;
    padding-bottom: 80px; /* for bottom nav */
}

a { text-decoration: none; color: inherit; }

/* ── Typography ── */
.h1 { font-size: 1.5rem; font-weight: 700; }
.h2 { font-size: 1.25rem; font-weight: 700; }
.h3 { font-size: 1.1rem; font-weight: 600; }
.text-sm { font-size: 0.875rem; }
.text-xs { font-size: 0.75rem; }
.text-muted { color: var(--text-muted); }
.font-bold { font-weight: 700; }

/* ── Layout Components ── */
.container {
    max-width: 500px;
    margin: 0 auto;
    padding: 1.25rem;
}

.card {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 1.25rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    margin-bottom: 1rem;
    transition: transform 0.2s;
}

.card:active { transform: scale(0.98); }

.glass {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

/* ── Bottom Navigation ── */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 70px;
    background: var(--bg-card);
    display: flex;
    justify-content: space-around;
    align-items: center;
    border-top: 1px solid var(--border);
    z-index: 1000;
    padding-bottom: env(safe-area-inset-bottom);
}

.nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-muted);
    font-size: 0.7rem;
    font-weight: 500;
    transition: all 0.3s;
}

.nav-item i {
    font-size: 1.25rem;
    margin-bottom: 4px;
}

.nav-item.active {
    color: var(--primary);
}

.nav-item.active i {
    transform: translateY(-2px);
}

/* ── Buttons ── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all 0.2s;
    gap: 0.5rem;
    width: 100%;
}

.btn-primary { background: var(--primary); color: white; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-secondary { background: var(--secondary); color: white; }
.btn-outline { background: transparent; border: 1px solid var(--border); }

/* ── Status Badges ── */
.badge {
    padding: 0.25rem 0.6rem;
    border-radius: 20px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
}

.badge-success { background: #dcfce7; color: #166534; }
.badge-warning { background: #fef9c3; color: #854d0e; }
.badge-danger { background: #fee2e2; color: #991b1b; }
.badge-info { background: #dbeafe; color: #1e40af; }

/* ── Forms ── */
.form-group { margin-bottom: 1rem; }
.form-label { display: block; font-size: 0.875rem; font-weight: 500; margin-bottom: 0.5rem; }
.form-control {
    width: 100%;
    padding: 0.75rem 1rem;
    border-radius: 12px;
    border: 1px solid var(--border);
    outline: none;
    transition: border-color 0.2s;
}
.form-control:focus { border-color: var(--primary); }

/* ── Utility ── */
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: 0.5rem; }
.mt-4 { margin-top: 1rem; }
.mb-4 { margin-bottom: 1rem; }
.text-center { text-align: center; }

/* ── Custom Animations ── */
@keyframes slideUp {
    from { transform: translateY(20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.animate-up { animation: slideUp 0.4s ease-out forwards; }

/* ── Check-in Card ── */
.attendance-card {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    color: white;
}
.attendance-card .text-muted { color: rgba(255,255,255,0.7); }

/* ── List Items ── */
.list-item {
    display: flex;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid var(--border);
}
.list-item:last-child { border-bottom: none; }