/* Online Quiz System - Professional Business Design */

:root {
    --primary: #1e40af;
    --primary-dark: #1e3a8a;
    --primary-light: #3b82f6;
    --accent: #0ea5e9;
    --success: #059669;
    --danger: #dc2626;
    --warning: #d97706;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-600: #4b5563;
    --gray-800: #1f2937;
    --gray-900: #111827;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    color: var(--gray-800);
    background: var(--gray-50);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--primary);
    text-decoration: none;
}

a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 24px;
    font-size: 14px;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-success {
    background: var(--success);
    color: white;
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

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

.btn-sm {
    padding: 6px 16px;
    font-size: 13px;
}

/* Cards */
.card {
    background: white;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    padding: 24px;
    margin-bottom: 20px;
}

.card-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 16px;
    color: var(--gray-900);
}

/* Forms */
.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    color: var(--gray-700);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--gray-300);
    border-radius: 8px;
    font-size: 14px;
    transition: border-color 0.2s;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(30, 64, 175, 0.2);
}

.form-error {
    color: var(--danger);
    font-size: 13px;
    margin-top: 4px;
}

/* Alerts */
.alert {
    padding: 14px 18px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert-success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
}

.alert-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

.alert-warning {
    background: #fef3c7;
    color: #92400e;
    border: 1px solid #fde68a;
}

/* Header / Navbar */
.navbar {
    background: white;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    padding: 16px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.navbar-brand {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
}

.navbar-nav {
    display: flex;
    gap: 24px;
    align-items: center;
}

.navbar-nav a {
    text-decoration: none;
    color: var(--gray-600);
    font-weight: 500;
}

.navbar-nav a:hover {
    color: var(--primary);
}

/* Footer */
.footer {
    background: var(--gray-800);
    color: white;
    padding: 24px 0;
    margin-top: auto;
    text-align: center;
    font-size: 14px;
}

/* Quiz specific */
.quiz-card {
    transition: transform 0.2s, box-shadow 0.2s;
}

.quiz-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.question-option {
    padding: 14px 18px;
    border: 2px solid var(--gray-200);
    border-radius: 8px;
    margin-bottom: 10px;
    cursor: pointer;
    transition: all 0.2s;
}

.question-option:hover {
    border-color: var(--primary-light);
    background: #eff6ff;
}

.question-option.selected {
    border-color: var(--primary);
    background: #dbeafe;
}

.question-option.correct {
    border-color: var(--success);
    background: #d1fae5;
}

.question-option.wrong {
    border-color: var(--danger);
    background: #fee2e2;
}