:root {
    /* Premium Corporate Palette (HSL for consistency) */
    --primary-h: 221;
    --primary-s: 83%;
    --primary-l: 53%;
    
    --accent-color: hsl(var(--primary-h), var(--primary-s), var(--primary-l));
    --accent-hover: hsl(var(--primary-h), var(--primary-s), 45%);
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --glass-bg: rgba(255, 255, 255, 0.8);
    --glass-border: rgba(226, 232, 240, 0.8);
    --glass-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -2px rgba(0, 0, 0, 0.02);
    
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
}

.dark-mode {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --glass-bg: rgba(30, 41, 59, 0.8);
    --glass-border: rgba(255, 255, 255, 0.05);
    --glass-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3);
}

* { box-sizing: border-box; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

body {
    margin: 0;
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.5;
    transition: background 0.3s ease, color 0.3s ease;
    padding-bottom: 80px;
}

.glass-container {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    border-radius: 24px;
    margin: 20px auto 100px auto;
    width: 95%;
    max-width: 1200px;
    overflow: hidden;
}

/* Typography Overhaul */
h1, h2, h3, h4 { font-weight: 700; letter-spacing: -0.025em; margin-top: 0; }
h2 { font-size: 1.8rem; }
h3 { font-size: 1.25rem; }

/* Premium Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    width: 100%;
    text-decoration: none;
    gap: 8px;
}

.btn:hover { background: var(--accent-hover); transform: translateY(-1px); box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25); }
.btn:active { transform: translateY(0); }

.btn-success { background: var(--success-color); }
.btn-success:hover { background: #059669; box-shadow: 0 4px 12px rgba(16, 185, 129, 0.25); }
.btn-danger { background: var(--danger-color); }
.btn-danger:hover { background: #dc2626; box-shadow: 0 4px 12px rgba(239, 68, 68, 0.25); }

/* Forms & Inputs */
.form-group { margin-bottom: 12px; }
label { display: block; font-size: 0.8rem; font-weight: 600; color: var(--text-secondary); margin-bottom: 6px; }

input, select, textarea {
    width: 100%;
    padding: 8px 12px;
    background: var(--card-bg);
    border: 1px solid var(--glass-border);
    border-radius: 10px;
    color: var(--text-primary);
    font-size: 0.9rem;
    font-family: inherit;
    transition: all 0.2s ease;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.08);
}

.form-grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-bottom: 12px; }

/* Widget-style Cards */
.report-card, .trip-card {
    background: var(--card-bg);
    border: 1px solid var(--glass-border);
    border-radius: 14px;
    padding: 14px;
    margin-bottom: 12px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.report-card:hover { transform: translateY(-2px); box-shadow: 0 12px 20px -5px rgba(0, 0, 0, 0.1); }

/* Custom Scrollbar */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--glass-border); border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-secondary); }

/* Animations */
@keyframes slideInLeft {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

@keyframes slideInRight {
    from { transform: translateX(-100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.tab-content { display: none; width: 100%; }
.tab-content.active { 
    display: block; 
    animation: slideUp 0.4s cubic-bezier(0.16, 1, 0.3, 1); 
}
.tab-content.slide-in-left {
    animation: slideInLeft 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}
.tab-content.slide-in-right {
    animation: slideInRight 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

/* Header & Nav Styling */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--glass-border);
    padding-bottom: 20px;
}

.logout-link { color: var(--danger-color); text-decoration: none; font-weight: 600; font-size: 0.9rem; transition: opacity 0.2s; }
.logout-link:hover { opacity: 0.8; }

/* Status Badges */
.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
}

.badge-pending { background: #fef3c7; color: #92400e; }
.badge-approved { background: #dcfce7; color: #166534; }
.badge-rejected { background: #fee2e2; color: #991b1b; }

/* Navigation Tab UI */
.bottom-nav {
    position: fixed; bottom: 0; left: 0; right: 0;
    background: var(--glass-bg); backdrop-filter: blur(30px);
    border-top: 1px solid var(--glass-border);
    display: flex; justify-content: center; align-items: center;
    padding: 8px 12px;
    z-index: 1000;
    gap: 8px;
}

.bottom-nav .nav-item {
    display: flex; flex-direction: column; align-items: center; justify-content: center;
    color: var(--text-secondary); text-decoration: none; font-size: 0.7rem;
    font-weight: 600; cursor: pointer; transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    height: 48px;
    flex: 1;
    max-width: 100px;
    border-radius: 12px;
}

.bottom-nav .nav-item.active {
    color: var(--accent-color);
    background: rgba(37, 99, 235, 0.08);
}

.dark-mode .bottom-nav .nav-item.active {
    background: rgba(37, 99, 235, 0.15);
}

.bottom-nav .nav-icon { font-size: 1.25rem; transition: transform 0.2s ease; margin-bottom: 2px; }
.bottom-nav .nav-item.active .nav-icon { transform: scale(1.1); }