/**
 * Modern Custom CSS for Conference Registration System
 * Primary Color: #286EAC
 */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
    --primary-color: #286EAC;
    --primary-dark: #1e5285;
    --primary-light: #4a8bc4;
    --primary-gradient: linear-gradient(135deg, #286EAC 0%, #1e5285 100%);
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --text-dark: #212529;
    --text-muted: #6c757d;
    --border-color: #e9ecef;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(180deg, #f0f4f8 0%, #ffffff 100%);
    color: var(--text-dark);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Modern Navbar */
.navbar-modern {
    background: var(--bg-white) !important;
    box-shadow: var(--shadow-sm);
    padding: 1rem 0;
    transition: all 0.3s ease;
}

.navbar-modern .navbar-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--text-dark) !important;
    text-decoration: none;
}

.navbar-modern .brand-icon {
    width: 40px;
    height: 40px;
    background: var(--primary-gradient);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
}

.navbar-modern .brand-text {
    color: var(--text-dark);
}

.navbar-modern .nav-link {
    color: var(--text-dark) !important;
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
    position: relative;
}

.navbar-modern .nav-link:hover,
.navbar-modern .nav-link.active {
    color: var(--primary-color) !important;
    background: rgba(40, 110, 172, 0.1);
}

.navbar-modern .nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 30px;
    height: 3px;
    background: var(--primary-color);
    border-radius: 2px;
}

/* Hero Section */
.registration-hero {
    background: var(--primary-gradient);
    color: white;
    padding: 4rem 0 6rem;
    position: relative;
    overflow: hidden;
}

.registration-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><circle cx="50" cy="50" r="2" fill="rgba(255,255,255,0.1)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 700px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 0.5rem 1.25rem;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.hero-title {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    font-weight: 400;
    opacity: 0.95;
    margin-bottom: 1rem;
}

.hero-location {
    font-size: 1rem;
    opacity: 0.9;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.hero-shape {
    position: absolute;
    bottom: -50px;
    left: 0;
    right: 0;
    height: 100px;
    background: var(--bg-white);
    clip-path: polygon(0 50%, 100% 0, 100% 100%, 0 100%);
}

/* Registration Container */
.registration-container {
    margin-top: -3rem;
    margin-bottom: 4rem;
    position: relative;
    z-index: 2;
}

.registration-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    border: none;
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.registration-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0,0,0,0.15);
}

.registration-card .card-body {
    padding: 3rem;
}

/* Form Sections */
.form-section {
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.form-section:last-of-type {
    border-bottom: none;
    margin-bottom: 2rem;
}

.section-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 2rem;
}

.section-icon {
    width: 48px;
    height: 48px;
    background: var(--primary-gradient);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    flex-shrink: 0;
    box-shadow: var(--shadow-md);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 0.25rem;
}

.section-subtitle {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin: 0;
}

/* Form Controls */
.form-label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-dark);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.form-label .text-danger {
    color: var(--danger-color) !important;
}

.form-control,
.form-select {
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    transition: all 0.3s ease;
    background: var(--bg-white);
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(40, 110, 172, 0.1);
    outline: none;
    background: var(--bg-white);
}

.form-control.is-valid,
.form-select.is-valid {
    border-color: var(--success-color);
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='%2328a745' d='m2.3 6.73.98-.98 1.98 1.98 3.96-3.96.98.98L5.26 8.7z'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 1rem;
}

.form-control.is-invalid,
.form-select.is-invalid {
    border-color: var(--danger-color);
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='%23dc3545'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath d='m5.8 3.6.4.4.4-.4.4.4-.4.4.4.4-.4-.4-.4.4-.4-.4.4-.4-.4-.4z'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    background-size: 1rem;
}

.invalid-feedback {
    display: block;
    font-size: 0.875rem;
    color: var(--danger-color);
    margin-top: 0.5rem;
}

/* Submit Button */
.submit-wrapper {
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
}

.btn-submit {
    width: 100%;
    background: var(--primary-gradient);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.btn-submit::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: left 0.5s;
}

.btn-submit:hover::before {
    left: 100%;
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(40, 110, 172, 0.4);
}

.btn-submit:active {
    transform: translateY(0);
}

.btn-submit:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
}

.btn-text,
.btn-loader {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

/* Checkbox */
.form-check {
    padding: 1rem;
    background: rgba(40, 110, 172, 0.05);
    border-radius: var(--radius-sm);
    border: 2px solid var(--border-color);
    transition: all 0.3s ease;
}

.form-check:hover {
    border-color: var(--primary-color);
    background: rgba(40, 110, 172, 0.1);
}

.form-check-input {
    width: 1.25rem;
    height: 1.25rem;
    margin-top: 0.15rem;
    cursor: pointer;
}

.form-check-input:checked {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.form-check-label {
    font-weight: 500;
    cursor: pointer;
    margin-left: 0.5rem;
}

/* Alert Styles */
.alert {
    border-radius: var(--radius-md);
    border: none;
    padding: 1rem 1.5rem;
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
}

.alert i {
    margin-right: 0.5rem;
    font-size: 1.1rem;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border-left: 4px solid var(--success-color);
}

.alert-danger {
    background: #f8d7da;
    color: #721c24;
    border-left: 4px solid var(--danger-color);
}

.alert-warning {
    background: #fff3cd;
    color: #856404;
    border-left: 4px solid var(--warning-color);
}

/* Footer */
.footer-modern {
    background: var(--text-dark);
    color: rgba(255, 255, 255, 0.8);
    padding: 2rem 0;
    margin-top: auto;
}

.footer-content {
    text-align: center;
    font-size: 0.9rem;
}

/* Password Toggle */
.password-toggle {
    position: relative;
}

.password-toggle .form-control {
    padding-right: 45px;
}

.password-toggle-btn {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 0.5rem;
    z-index: 10;
    transition: color 0.3s ease;
}

.password-toggle-btn:hover {
    color: var(--primary-color);
}

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

.registration-card {
    animation: fadeInUp 0.6s ease-out;
}

.form-section {
    animation: fadeInUp 0.6s ease-out;
    animation-fill-mode: both;
}

.form-section:nth-child(1) { animation-delay: 0.1s; }
.form-section:nth-child(2) { animation-delay: 0.2s; }
.form-section:nth-child(3) { animation-delay: 0.3s; }
.form-section:nth-child(4) { animation-delay: 0.4s; }

/* Responsive */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .registration-card .card-body {
        padding: 2rem 1.5rem;
    }
    
    .section-header {
        flex-direction: column;
        text-align: center;
    }
    
    .section-icon {
        margin: 0 auto;
    }
    
    .btn-submit {
        padding: 0.875rem 1.5rem;
        font-size: 1rem;
    }
}

/* Loading States */
.spinner-border-sm {
    width: 1rem;
    height: 1rem;
    border-width: 0.15em;
}

/* Primary Color Overrides */
.bg-primary {
    background: var(--primary-gradient) !important;
}

.btn-primary {
    background: var(--primary-gradient);
    border: none;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.text-primary {
    color: var(--primary-color) !important;
}