/* Main Shared Styles for AI Course Platform */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background: #050811;
    color: #e0e0e0;
    line-height: 1.6;
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    width: min(1200px, 100%);
    margin: 0 auto;
    padding: 0 16px;
}

/* HEADER */
header {
    position: sticky;
    top: 0;
    z-index: 50;
    backdrop-filter: blur(12px);
    background: rgba(5, 8, 17, 0.92);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    letter-spacing: 0.06em;
    font-size: 1rem;
    text-transform: uppercase;
}

.logo-badge {
    width: 30px;
    height: 30px;
    border-radius: 999px;
    background: radial-gradient(circle at 20% 0%, #4ecdc4, #2c5aa0);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.7rem;
    color: #fff;
}

.nav-links {
    display: flex;
    gap: 20px;
    font-size: 0.9rem;
}

.nav-links a {
    opacity: 0.8;
    transition: opacity 0.2s, transform 0.2s;
}

.nav-links a:hover {
    opacity: 1;
    transform: translateY(-1px);
}

.nav-cta {
    padding: 8px 16px;
    border-radius: 999px;
    background: linear-gradient(135deg, #4ecdc4, #2c5aa0);
    color: #050811;
    font-size: 0.85rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.15s;
}

.nav-cta:hover {
    transform: translateY(-1px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.45);
}

/* Buttons */
.btn-primary {
    padding: 12px 22px;
    border-radius: 999px;
    border: none;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    background: linear-gradient(135deg, #4ecdc4, #2c5aa0);
    color: #050811;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.4);
    transition: transform 0.15s, box-shadow 0.15s;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.55);
}

.btn-primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-secondary {
    padding: 12px 22px;
    border-radius: 999px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    background: transparent;
    color: #e0e0e0;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.3);
}

.btn-danger {
    padding: 12px 22px;
    border-radius: 999px;
    border: none;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    background: linear-gradient(135deg, #ff6b6b, #c92a2a);
    color: #fff;
    transition: transform 0.15s, box-shadow 0.15s;
}

.btn-danger:hover {
    transform: translateY(-1px);
    box-shadow: 0 10px 25px rgba(255, 107, 107, 0.4);
}

/* Cards */
.card {
    background: #1e1e1e;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.3);
    padding: 30px;
    margin-bottom: 30px;
    border: 1px solid #333;
}

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

.form-label {
    display: block;
    margin-bottom: 8px;
    color: #c1c1c1;
    font-size: 0.9rem;
    font-weight: 500;
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    background: #2d2d2d;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: #e0e0e0;
    font-size: 0.95rem;
    transition: all 0.3s;
}

.form-input:focus {
    outline: none;
    border-color: #4ecdc4;
    background: #333;
}

.form-input::placeholder {
    color: #666;
}

.form-error {
    color: #ff6b6b;
    font-size: 0.85rem;
    margin-top: 5px;
}

.form-success {
    color: #4ecdc4;
    font-size: 0.85rem;
    margin-top: 5px;
}

/* Alerts */
.alert {
    padding: 15px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 0.9rem;
}

.alert-success {
    background: rgba(78, 205, 196, 0.1);
    border: 1px solid rgba(78, 205, 196, 0.3);
    color: #4ecdc4;
}

.alert-error {
    background: rgba(255, 107, 107, 0.1);
    border: 1px solid rgba(255, 107, 107, 0.3);
    color: #ff6b6b;
}

.alert-warning {
    background: rgba(255, 193, 7, 0.1);
    border: 1px solid rgba(255, 193, 7, 0.3);
    color: #ffc107;
}

.alert-info {
    background: rgba(44, 90, 160, 0.1);
    border: 1px solid rgba(44, 90, 160, 0.3);
    color: #4ecdc4;
}

/* Loading Spinner */
.spinner {
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-top: 3px solid #4ecdc4;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #2d2d2d;
}

::-webkit-scrollbar-thumb {
    background: #4ecdc4;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #ff6b6b;
}

/* Responsive */
@media (max-width: 720px) {
    .nav-links {
        display: none;
    }

    .nav {
        gap: 10px;
    }
}

/* Utility Classes */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 10px; }
.mt-2 { margin-top: 20px; }
.mt-3 { margin-top: 30px; }

.mb-1 { margin-bottom: 10px; }
.mb-2 { margin-bottom: 20px; }
.mb-3 { margin-bottom: 30px; }

.hidden {
    display: none !important;
}

.flex {
    display: flex;
}

.flex-center {
    display: flex;
    justify-content: center;
    align-items: center;
}

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

.gap-1 { gap: 10px; }
.gap-2 { gap: 20px; }
.gap-3 { gap: 30px; }