/* ═══════════════════════════════════════════════════════════
   Zilele Tehnicii Studențești (ZTS) — Ediția a XIII-a
   Platforma AI Cyber Defense Challenge
   ═══════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
    /* Paletă cromatică tehnică, sobră și curată */
    --bg-main: #0b0e14;
    --bg-surface: #121722;
    --bg-surface-hover: #182030;
    --bg-element: #1c2436;
    --bg-input: #0f141f;

    --border-color: #242d40;
    --border-focus: #3b82f6;

    --text-main: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --brand-primary: #2563eb;
    --brand-primary-hover: #1d4ed8;

    --status-open-bg: #064e3b;
    --status-open-text: #34d399;
    --status-locked-bg: #1e293b;
    --status-locked-text: #94a3b8;

    --accent-blue: #38bdf8;
    --accent-green: #10b981;
    --accent-red: #ef4444;
    --accent-amber: #f59e0b;

    --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
}

/* Structure */
.container {
    width: 100%;
    max-width: 1140px;
    margin: 0 auto;
    padding: 0 20px;
}

.main-content {
    flex: 1;
    padding: 40px 0 60px;
}

/* Header & Nav */
.site-header {
    background-color: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 50;
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 68px;
}

.brand-link {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text-main);
}

.brand-badge {
    background: var(--brand-primary);
    color: #ffffff;
    font-weight: 800;
    font-size: 0.8rem;
    padding: 4px 8px;
    border-radius: var(--radius-sm);
    letter-spacing: 0.5px;
}

.brand-title {
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--text-main);
}

.brand-subtitle {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 500;
}

.nav-menu {
    display: flex;
    gap: 8px;
    list-style: none;
}

.nav-item a {
    color: var(--text-secondary);
    text-decoration: none;
    padding: 8px 14px;
    font-size: 0.9rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    transition: background-color 0.15s ease, color 0.15s ease;
}

.nav-item a:hover {
    color: var(--text-main);
    background-color: var(--bg-element);
}

.nav-item a.active {
    color: var(--text-main);
    background-color: var(--bg-element);
    border: 1px solid var(--border-color);
}

/* Page Titles */
.page-header {
    margin-bottom: 32px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 20px;
}

.page-title {
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--text-main);
    letter-spacing: -0.02em;
    margin-bottom: 6px;
}

.page-description {
    font-size: 0.95rem;
    color: var(--text-secondary);
    max-width: 750px;
}

/* Section Header */
.section-header {
    margin: 32px 0 20px;
}

.section-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: -0.01em;
}

/* Cards & Panel */
.panel {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    margin-bottom: 24px;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 20px;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(450px, 1fr));
    gap: 20px;
}

/* Level Cards */
.level-box {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    display: flex;
    flex-direction: column;
}

.level-box-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 14px;
}

.level-tag {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent-blue);
    background-color: rgba(56, 189, 248, 0.1);
    padding: 2px 8px;
    border-radius: 4px;
    border: 1px solid rgba(56, 189, 248, 0.2);
}

.badge-status {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 3px 10px;
    border-radius: 20px;
}

.badge-status.open {
    background-color: var(--status-open-bg);
    color: var(--status-open-text);
}

.badge-status.locked {
    background-color: var(--status-locked-bg);
    color: var(--status-locked-text);
}

.level-box h3 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.level-box p {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 18px;
    flex: 1;
}

.level-meta-row {
    display: flex;
    justify-content: space-between;
    padding-top: 14px;
    border-top: 1px solid var(--border-color);
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Table Design */
.table-wrapper {
    width: 100%;
    overflow-x: auto;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
    text-align: left;
}

.data-table th {
    background-color: var(--bg-element);
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
}

.data-table td {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
}

.data-table tr:last-child td {
    border-bottom: none;
}

.data-table tr:hover td {
    background-color: var(--bg-surface-hover);
}

.mono {
    font-family: var(--font-mono);
}

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

.form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.form-control {
    width: 100%;
    padding: 10px 14px;
    background-color: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-main);
    font-family: var(--font-sans);
    font-size: 0.9rem;
}

.form-control:focus {
    outline: none;
    border-color: var(--border-focus);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.875rem;
    font-family: var(--font-sans);
    cursor: pointer;
    border: none;
    text-decoration: none;
    transition: background-color 0.15s ease;
}

.btn-primary {
    background-color: var(--brand-primary);
    color: #ffffff;
}

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

.btn-secondary {
    background-color: var(--bg-element);
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--bg-surface-hover);
}

.btn-danger {
    background-color: #dc2626;
    color: #ffffff;
}

.btn-success {
    background-color: #059669;
    color: #ffffff;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* Alert Boxes */
.alert {
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    margin-bottom: 20px;
    border: 1px solid transparent;
}

.alert-info {
    background-color: rgba(56, 189, 248, 0.1);
    border-color: rgba(56, 189, 248, 0.25);
    color: var(--accent-blue);
}

.alert-success {
    background-color: rgba(16, 185, 129, 0.1);
    border-color: rgba(16, 185, 129, 0.25);
    color: var(--accent-green);
}

.alert-error {
    background-color: rgba(239, 68, 68, 0.1);
    border-color: rgba(239, 68, 68, 0.25);
    color: var(--accent-red);
}

.alert-warning {
    background-color: rgba(245, 158, 11, 0.1);
    border-color: rgba(245, 158, 11, 0.25);
    color: var(--accent-amber);
}

/* Drop Zone */
.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-md);
    padding: 36px 20px;
    text-align: center;
    background-color: var(--bg-input);
    cursor: pointer;
    transition: border-color 0.15s ease;
}

.drop-zone:hover, .drop-zone.active {
    border-color: var(--brand-primary);
}

.drop-zone-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.drop-zone-text strong {
    color: var(--text-main);
}

/* Tabs */
.tab-list {
    display: flex;
    gap: 6px;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 24px;
}

.tab-btn {
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    padding: 10px 16px;
    font-family: var(--font-sans);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
}

.tab-btn:hover {
    color: var(--text-main);
}

.tab-btn.active {
    color: var(--brand-primary);
    border-bottom-color: var(--brand-primary);
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-surface);
    padding: 24px 0;
    font-size: 0.85rem;
    color: var(--text-muted);
}

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

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    margin-left: 16px;
}

.footer-links a:hover {
    color: var(--text-main);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        height: auto;
        padding: 16px 0;
        gap: 12px;
    }
    .grid-3, .grid-2 {
        grid-template-columns: 1fr;
    }
    .footer-content {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
}