:root {
    /* Light Theme Variables */
    --primary-color: #4F46E5; /* Indigo 600 */
    --primary-hover: #4338CA;
    --secondary-color: #64748b;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --hero-gradient: linear-gradient(135deg, #4F46E5 0%, #38BDF8 100%);
    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.01);
    --card-shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.01);
}

[data-bs-theme="dark"] {
    /* Dark Theme Variables */
    --primary-color: #6366f1; /* Indigo 500 */
    --primary-hover: #818cf8;
    --secondary-color: #94a3b8;
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-main: #f8fafc;
    --text-muted: #cbd5e1;
    --border-color: #334155;
    --hero-gradient: linear-gradient(135deg, #1e1b4b 0%, #312e81 100%);
    --card-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.2);
    --card-shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.5), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
}

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Navbar Customization */
.navbar {
    background-color: rgba(var(--card-bg), 0.8) !important;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
}

/* For dark mode navbar background */
[data-bs-theme="dark"] .navbar {
    background-color: rgba(30, 41, 59, 0.8) !important;
}

.navbar-brand {
    font-weight: 800;
    letter-spacing: -0.5px;
    color: var(--primary-color) !important;
    font-size: 1.5rem;
}

/* Hero Section */
.hero-section {
    background: var(--hero-gradient);
    color: white;
    padding: 120px 0 100px 0;
    border-radius: 0 0 40px 40px;
    margin-bottom: 60px;
    box-shadow: var(--card-shadow);
}

[data-bs-theme="dark"] .hero-section {
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    letter-spacing: -1px;
    margin-bottom: 24px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

/* Cards */
.custom-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    overflow: hidden;
}

.custom-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--card-shadow-hover);
}

.card-title {
    color: var(--text-main);
}

/* Text Colors */
.text-muted {
    color: var(--text-muted) !important;
}

/* Forms */
.form-label {
    color: var(--text-main);
}

.form-control, .form-select, .input-group-text {
    background-color: var(--bg-color);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 14px 20px;
    transition: all 0.3s ease;
}

.form-control:focus, .form-select:focus {
    background-color: var(--card-bg);
    color: var(--text-main);
    box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.15);
    border-color: var(--primary-color);
}

/* For dark mode inputs */
[data-bs-theme="dark"] .form-control::placeholder {
    color: var(--text-muted);
}

/* Buttons */
.btn-primary {
    border-radius: 12px;
    padding: 14px 28px;
    font-weight: 600;
    background-color: var(--primary-color);
    border: none;
    box-shadow: 0 4px 6px -1px rgba(99, 102, 241, 0.4), 0 2px 4px -1px rgba(99, 102, 241, 0.2);
    transition: all 0.3s ease;
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(99, 102, 241, 0.5), 0 4px 6px -2px rgba(99, 102, 241, 0.25);
}

.btn-outline-primary {
    color: var(--primary-color);
    border-color: var(--primary-color);
    border-radius: 12px;
}

.btn-outline-primary:hover {
    background-color: var(--primary-color);
    color: white;
}

/* Checkboxes & Radios */
.btn-check:checked + .btn-outline-primary {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 6px -1px rgba(99, 102, 241, 0.4);
}

/* Itinerary Details */
.itinerary-day {
    background-color: var(--card-bg);
    border-radius: 20px;
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--card-shadow);
    border-left: 6px solid var(--primary-color);
}

.list-group-item {
    background-color: transparent;
    color: var(--text-main);
    border-color: var(--border-color);
}

/* Footer */
footer {
    background-color: var(--card-bg);
    padding: 40px 0;
    margin-top: 60px;
    border-top: 1px solid var(--border-color);
}

/* Theme Toggle Button */
.theme-toggle {
    background: transparent;
    border: none;
    color: var(--text-main);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--border-color);
}