/* ===================================
   GENERAL & LAYOUT
   =================================== */

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #e9ecef 100%);
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    color: #2c3e50;
    line-height: 1.6;
}

.container {
    background-color: #ffffff;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    padding: 35px;
    margin-top: 20px;
    margin-bottom: 30px;
    max-width: 1200px;
}

/* ===================================
   LOGO STYLING
   =================================== */

.text-center img[alt="NADC Logo"] {
    max-width: 100%;
    height: auto;
    margin: 15px auto !important;
    display: block;
}

/* ===================================
   HEADINGS & TYPOGRAPHY
   =================================== */

h3 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 25px;
    letter-spacing: -0.5px;
}

h4 {
    font-size: 1.4rem;
    font-weight: 600;
    color: #34495e;
    margin-bottom: 20px;
}

h5 {
    font-size: 1.2rem;
    font-weight: 600;
    color: #34495e;
}

p, label {
    font-size: 1rem;
    line-height: 1.7;
}

/* ===================================
   NAVIGATION TABS
   =================================== */

.panel.with-tabs {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
}

.panel-heading {
    background: linear-gradient(135deg, #ffffff 0%, #f8f9fa 100%);
    margin-bottom: 0;
    padding: 0;
    border-bottom: 2px solid #e9ecef;
}

.nav-tabs {
    border-bottom: none;
    flex-wrap: wrap;
    gap: 5px;
    padding: 15px 15px 0 15px;
}

.nav-tabs .nav-item {
    margin-bottom: 0;
}

.nav-tabs .nav-link {
    border: 2px solid transparent;
    border-radius: 8px 8px 0 0;
    color: #6c757d;
    font-weight: 600;
    padding: 12px 20px;
    transition: all 0.3s ease;
    background-color: transparent;
    font-size: 0.95rem;
}

.nav-tabs .nav-link:hover {
    background-color: #f8f9fa;
    color: #1a1a1a;
    border-color: transparent;
}

.nav-tabs .nav-link.active {
    background: linear-gradient(135deg, #1a1a1a 0%, #000000 100%);
    color: white !important;
    border-color: transparent;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.3);
}

/* ===================================
   FORM STYLING
   =================================== */

.panel-body {
    padding: 30px;
    background-color: #ffffff;
}

.form-section {
    margin-bottom: 20px;
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid #e9ecef;
}

.form-section .panel-heading {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border-bottom: 2px solid #dee2e6;
    padding: 15px 20px;
}

.form-section .panel-title a {
    color: #2c3e50;
    font-weight: 600;
    text-decoration: none;
    font-size: 1.1rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    font-weight: 600;
    color: #34495e;
    margin-bottom: 8px;
    display: block;
    font-size: 0.95rem;
}

.form-control {
    border: 2px solid #e9ecef;
    border-radius: 8px;
    padding: 12px 15px;
    font-size: 1rem;
    transition: all 0.3s ease;
    background-color: #ffffff;
}

.form-control:focus {
    border-color: #1a1a1a;
    box-shadow: 0 0 0 0.2rem rgba(26, 26, 26, 0.1);
    outline: none;
    background-color: #ffffff;
}

.form-control::placeholder {
    color: #adb5bd;
}

select.form-control {
    cursor: pointer;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%231a1a1a' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 35px;
}

textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

.form-check-input {
    margin-top: 0.35rem;
    cursor: pointer;
}

.form-check-label {
    cursor: pointer;
    color: #495057;
    font-weight: 500;
}

/* ===================================
   BUTTONS
   =================================== */

.btn {
    border-radius: 8px;
    padding: 12px 28px;
    font-weight: 600;
    font-size: 1rem;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: linear-gradient(135deg, #1a1a1a 0%, #000000 100%);
    color: white;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #333333 0%, #1a1a1a 100%);
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
    color: white;
}

.btn-primary:active {
    transform: translateY(0);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #5a6268;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(108, 117, 125, 0.3);
}

.btn-success {
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: white;
}

.btn-success:hover {
    background: linear-gradient(135deg, #218838 0%, #1aa179 100%);
    transform: translateY(-2px);
}

/* ===================================
   ALERTS
   =================================== */

.alert {
    border-radius: 10px;
    padding: 18px 22px;
    border: none;
    margin-bottom: 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.alert-success {
    background: linear-gradient(135deg, #d4edda 0%, #c3e6cb 100%);
    color: #155724;
    border-left: 4px solid #28a745;
}

.alert-info {
    background: linear-gradient(135deg, #d1ecf1 0%, #bee5eb 100%);
    color: #0c5460;
    border-left: 4px solid #17a2b8;
}

.alert-warning {
    background: linear-gradient(135deg, #fff3cd 0%, #ffeaa7 100%);
    color: #856404;
    border-left: 4px solid #ffc107;
}

.alert-danger {
    background: linear-gradient(135deg, #f8d7da 0%, #f5c6cb 100%);
    color: #721c24;
    border-left: 4px solid #dc3545;
}

.alert-heading {
    font-weight: 700;
    margin-bottom: 10px;
}

/* ===================================
   REQUIRED INDICATOR
   =================================== */

.text-danger {
    color: #dc3545 !important;
    font-weight: 700;
}

/* ===================================
   RESPONSIVE DESIGN
   =================================== */

@media (max-width: 992px) {
    .nav-tabs {
        font-size: 0.85rem;
    }

    .nav-tabs .nav-link {
        padding: 10px 15px;
    }

    .container {
        padding: 25px;
    }
}

@media (max-width: 768px) {
    h3 {
        font-size: 1.5rem;
    }

    .nav-tabs {
        flex-direction: column;
    }

    .nav-tabs .nav-link {
        border-radius: 6px;
        margin-bottom: 5px;
    }

    .container {
        padding: 20px;
        border-radius: 8px;
    }

    .btn {
        width: 100%;
        margin-bottom: 10px;
    }
}

@media (max-width: 576px) {
    .panel-body {
        padding: 20px;
    }

    h3 {
        font-size: 1.3rem;
    }
}