:root {
    /* Premium Modern Palette - Indigo & Slate */
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --primary-light: #eef2ff;

    --secondary: #64748b;
    --accent: #0ea5e9;

    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;

    --bg-main: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;

    --border-color: #e2e8f0;
    --input-bg: #ffffff;

    /* Shadows & Effects */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 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);
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-blur: blur(12px);

    --radius: 12px;
    --radius-lg: 16px;

    /* iPhone 14 Safe Areas */
    --safe-top: env(safe-area-inset-top);
    --safe-bottom: env(safe-area-inset-bottom);
}

* {
    -webkit-tap-highlight-color: transparent;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    line-height: 1.5;
    padding-bottom: calc(70px + var(--safe-bottom));
    /* Leave space for mobile bottom nav */
}

@media (min-width: 992px) {
    body {
        padding-bottom: 0;
    }
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--text-main);
}

/* Glassmorphism Classes */
.glass {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

/* Cards */
.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    position: relative;
    overflow: visible !important;
}

.card:hover {
    box-shadow: var(--shadow-md);
    /* transform: translateY(-2px); Removed to fix dropdown z-index issues */
}

.card-header {
    background-color: transparent;
    border-bottom: 1px solid var(--border-color);
    padding: 1.25rem;
    font-weight: 600;
}

/* Buttons */
.btn {
    border-radius: 10px;
    padding: 0.625rem 1.25rem;
    font-weight: 600;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary {
    background-color: var(--primary);
    border: none;
    box-shadow: 0 4px 6px -1px rgba(79, 70, 229, 0.2);
}

.btn-primary:hover,
.btn-primary:active {
    background-color: var(--primary-hover);
    transform: scale(0.98);
}

.btn-success {
    background-color: var(--success);
    border: none;
}

/* Modern Navbar */
.navbar {
    background: var(--glass-bg) !important;
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--border-color);
    padding: 0.75rem 0;
    z-index: 1000;
}

.navbar-brand {
    font-weight: 800;
    font-size: 1.25rem;
    color: var(--primary) !important;
}

.nav-link {
    font-weight: 500;
    color: var(--text-muted) !important;
    padding: 0.5rem 1rem !important;
    border-radius: 8px;
    transition: all 0.2s;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary) !important;
    background-color: var(--primary-light);
}

/* Bottom Navigation (Mobile Only) */
.mobile-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: calc(65px + var(--safe-bottom));
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: space-around;
    align-items: center;
    padding-bottom: var(--safe-bottom);
    z-index: 1050;
    box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.05);
}

.mobile-nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.7rem;
    font-weight: 500;
    width: 16%;
}

.mobile-nav-item i {
    font-size: 1.4rem;
    margin-bottom: 2px;
}

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

/* Dashboard Schedule Layout */
.schedule-card {
    border-left: 4px solid var(--primary);
}

.schedule-time {
    font-weight: 700;
    color: var(--primary);
    width: 80px;
}

/* Utility */
.text-xs {
    font-size: 0.75rem;
}

.text-sm {
    font-size: 0.875rem;
}

.fw-semibold {
    font-weight: 600;
}

/* Custom Inputs */
.form-control,
.form-select {
    border-radius: 10px;
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px var(--primary-light);
}

@media (max-width: 991px) {
    .desktop-only {
        display: none !important;
    }
}

@media (min-width: 992px) {
    .mobile-only {
        display: none !important;
    }
}