@import url('https://fonts.googleapis.com/css2?family=Syne:wght@400;600;700;800&family=DM+Sans:ital,opsz,wght@0,9..40,300;0,9..40,400;0,9..40,500;1,9..40,300&family=JetBrains+Mono:wght@400;500&display=swap');

/* ============================================================
   VARIABLES & RESET
   ============================================================ */
:root {
    --bg:          #07090f;
    --surface:     #0f1420;
    --card:        #141b2d;
    --card-hover:  #1a2338;
    --border:      #1e2d4a;
    --border-light:#253454;
    --gold:        #f0a500;
    --gold-dim:    #c98a00;
    --blue:        #3b82f6;
    --blue-dim:    #2563eb;
    --green:       #10b981;
    --red:         #ef4444;
    --text:        #e8edf5;
    --text-muted:  #7a8ba8;
    --text-dim:    #4a5a72;
    --font-head:   'Syne', sans-serif;
    --font-body:   'DM Sans', sans-serif;
    --font-mono:   'JetBrains Mono', monospace;
    --radius:      12px;
    --radius-sm:   8px;
    --shadow:      0 4px 24px rgba(0,0,0,0.4);
    --shadow-lg:   0 8px 48px rgba(0,0,0,0.6);
    --glow-gold:   0 0 24px rgba(240,165,0,0.15);
    --glow-blue:   0 0 24px rgba(59,130,246,0.15);
}

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

html { scroll-behavior: smooth; }

body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.65;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-image:
        radial-gradient(ellipse 80% 50% at 50% -10%, rgba(59,130,246,0.08) 0%, transparent 70%),
        linear-gradient(180deg, rgba(240,165,0,0.03) 0%, transparent 30%);
}

/* ============================================================
   GRID OVERLAY
   ============================================================ */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image:
        linear-gradient(rgba(30,45,74,0.4) 1px, transparent 1px),
        linear-gradient(90deg, rgba(30,45,74,0.4) 1px, transparent 1px);
    background-size: 48px 48px;
    pointer-events: none;
    z-index: 0;
}

main, nav, footer { position: relative; z-index: 1; }

/* ============================================================
   NAVBAR
   ============================================================ */
.navbar {
    background: rgba(7,9,15,0.85);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 0 2rem;
}

.nav-inner {
    max-width: 1100px;
    margin: 0 auto;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-brand {
    font-family: var(--font-head);
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--gold);
    text-decoration: none;
    letter-spacing: 0.02em;
    transition: opacity 0.2s;
}
.nav-brand:hover { opacity: 0.8; }

.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.4rem 0.9rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}
.nav-link:hover {
    color: var(--text);
    border-color: var(--border-light);
    background: var(--card);
}

/* ============================================================
   HERO / INDEX PAGE
   ============================================================ */
.hero {
    max-width: 820px;
    margin: 0 auto;
    padding: 4rem 2rem 3rem;
    flex: 1;
}

.hero-text {
    text-align: center;
    margin-bottom: 2.5rem;
    animation: fadeUp 0.6s ease both;
}

.hero-text h1 {
    font-family: var(--font-head);
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, #ffffff 0%, var(--gold) 60%, #f0c040 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1rem;
}

.hero-text p {
    color: var(--text-muted);
    font-size: 1.1rem;
    max-width: 560px;
    margin: 0 auto;
    line-height: 1.7;
}

/* ============================================================
   CARD
   ============================================================ */
.card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2.5rem;
    box-shadow: var(--shadow);
    animation: fadeUp 0.6s 0.1s ease both;
}

/* ============================================================
   FORM
   ============================================================ */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.required { color: var(--gold); }
.optional {
    color: var(--text-dim);
    font-weight: 400;
    text-transform: none;
    letter-spacing: 0;
    font-size: 0.8rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.85rem 1rem;
    color: var(--text);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: all 0.2s;
    resize: vertical;
    outline: none;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-dim);
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--gold-dim);
    box-shadow: 0 0 0 3px rgba(240,165,0,0.1);
    background: rgba(240,165,0,0.03);
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background: var(--gold);
    color: #07090f;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.85rem 2rem;
    font-family: var(--font-head);
    font-size: 0.95rem;
    font-weight: 700;
    letter-spacing: 0.02em;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s;
    width: 100%;
    margin-top: 0.5rem;
}

.btn-primary:hover {
    background: #ffc62b;
    transform: translateY(-1px);
    box-shadow: var(--glow-gold);
}

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

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: transparent;
    color: var(--text-muted);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.6rem 1.1rem;
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s;
}

.btn-secondary:hover {
    color: var(--text);
    border-color: var(--border-light);
    background: var(--card-hover);
}

.btn-danger {
    display: inline-flex;
    align-items: center;
    background: transparent;
    color: var(--red);
    border: 1px solid rgba(239,68,68,0.3);
    border-radius: var(--radius-sm);
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s;
}
.btn-danger:hover {
    background: rgba(239,68,68,0.1);
    border-color: var(--red);
}

/* ============================================================
   ALERTS
   ============================================================ */
.alert {
    border-radius: var(--radius-sm);
    padding: 0.85rem 1.2rem;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    border: 1px solid;
}

.alert-error {
    background: rgba(239,68,68,0.08);
    border-color: rgba(239,68,68,0.3);
    color: #fca5a5;
}

.alert-success {
    background: rgba(16,185,129,0.08);
    border-color: rgba(16,185,129,0.3);
    color: #6ee7b7;
}

/* ============================================================
   RESULT PAGE
   ============================================================ */
.result-page {
    max-width: 1000px;
    margin: 0 auto;
    padding: 2.5rem 2rem;
    flex: 1;
}

.result-header {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
    animation: fadeUp 0.5s ease both;
}

.result-header h1 {
    font-family: var(--font-head);
    font-size: clamp(1.5rem, 3vw, 2.2rem);
    font-weight: 800;
    letter-spacing: -0.02em;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.model-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: rgba(59,130,246,0.1);
    color: var(--blue);
    border: 1px solid rgba(59,130,246,0.25);
    border-radius: 20px;
    padding: 0.2rem 0.75rem;
    font-size: 0.78rem;
    font-family: var(--font-mono);
    margin-bottom: 1.2rem;
}

.model-badge::before { content: '⚡'; }

.action-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
    align-items: center;
}

/* ============================================================
   TABS
   ============================================================ */
.tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.tab-btn {
    background: none;
    border: none;
    border-bottom: 2px solid transparent;
    padding: 0.7rem 1.2rem;
    color: var(--text-muted);
    font-family: var(--font-body);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    margin-bottom: -1px;
}

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

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

.tab-content { display: none; }
.tab-content.active {
    display: block;
    animation: fadeUp 0.3s ease both;
}

/* ============================================================
   SOP DOCUMENT STYLING
   ============================================================ */
.sop-document {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 3rem;
    line-height: 1.8;
    box-shadow: var(--shadow);
}

.sop-document h1 {
    font-family: var(--font-head);
    font-size: 1.9rem;
    font-weight: 800;
    color: var(--gold);
    border-bottom: 2px solid var(--border);
    padding-bottom: 1rem;
    margin-bottom: 2rem;
    letter-spacing: -0.01em;
}

.sop-document h2 {
    font-family: var(--font-head);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--text);
    background: var(--surface);
    border-left: 3px solid var(--gold);
    padding: 0.5rem 1rem;
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    margin: 2rem 0 1rem;
    letter-spacing: 0.01em;
    text-transform: uppercase;
}

.sop-document h3 {
    font-family: var(--font-head);
    font-size: 1rem;
    font-weight: 700;
    color: var(--blue);
    margin: 1.5rem 0 0.5rem;
}

.sop-document p {
    color: var(--text);
    margin-bottom: 0.8rem;
}

.sop-document ul,
.sop-document ol {
    margin: 0.5rem 0 1rem 1.5rem;
    color: var(--text);
}

.sop-document li {
    margin-bottom: 0.4rem;
    line-height: 1.7;
}

.sop-document strong {
    color: var(--gold);
    font-weight: 600;
}

.sop-document code {
    font-family: var(--font-mono);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 0.1rem 0.4rem;
    font-size: 0.85em;
    color: var(--blue);
}

/* ============================================================
   MERMAID DIAGRAM
   ============================================================ */
.bpmn-toolbar {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.bpmn-label {
    font-family: var(--font-head);
    font-weight: 700;
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-right: auto;
}

.mermaid-wrapper {
    background: #ffffff;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    padding: 2rem;
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow);
    overflow: auto;
}

.mermaid-wrapper .mermaid {
    width: 100%;
    display: flex;
    justify-content: center;
}

.mermaid-wrapper svg {
    max-width: 100%;
    height: auto;
}

/* ============================================================
   HISTORY PAGE
   ============================================================ */
.history-page {
    max-width: 1100px;
    margin: 0 auto;
    padding: 2.5rem 2rem;
    flex: 1;
}

.history-page h1 {
    font-family: var(--font-head);
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    margin-bottom: 2rem;
    color: var(--text);
}

.history-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.2rem;
}

.history-card {
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: all 0.2s;
    box-shadow: var(--shadow);
}

.history-card:hover {
    border-color: var(--border-light);
    background: var(--card-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.history-card h3 {
    font-family: var(--font-head);
    font-size: 1rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.history-desc {
    color: var(--text-muted);
    font-size: 0.875rem;
    line-height: 1.6;
    margin-bottom: 1rem;
}

.history-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.4rem;
}

.date {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--text-dim);
}

.history-actions {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.empty-state p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.empty-state .btn-primary { width: auto; }

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
    border-top: 1px solid var(--border);
    padding: 1.5rem 2rem;
    text-align: center;
    position: relative;
    z-index: 1;
}

.footer p {
    color: var(--text-dim);
    font-size: 0.8rem;
    line-height: 1.6;
}

.footer .course-info {
    display: block;
    font-size: 0.75rem;
    color: var(--text-dim);
    margin-top: 0.2rem;
    font-family: var(--font-mono);
}

/* ============================================================
   LOADING OVERLAY
   ============================================================ */
.loading-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(7,9,15,0.92);
    backdrop-filter: blur(8px);
    z-index: 999;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1.5rem;
}

.loading-overlay.active { display: flex; }

.loading-spinner {
    width: 56px;
    height: 56px;
    border: 3px solid var(--border);
    border-top-color: var(--gold);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

.loading-text {
    font-family: var(--font-head);
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text);
}

.loading-sub {
    color: var(--text-muted);
    font-size: 0.875rem;
    font-family: var(--font-mono);
}

/* ============================================================
   ANIMATIONS
   ============================================================ */
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(16px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ============================================================
   PRINT STYLES
   ============================================================ */
@media print {
    .print-hide,
    nav,
    .tabs,
    .action-buttons,
    .tab-btn,
    footer,
    #tab-bpmn { display: none !important; }

    body {
        background: white;
        color: black;
    }

    body::before { display: none; }

    .sop-document {
        background: white;
        color: black;
        border: none;
        padding: 0;
        box-shadow: none;
    }

    .sop-document h1 { color: #1a1a1a; border-color: #ccc; }

    .sop-document h2 {
        color: #1a1a1a;
        background: #f5f5f5;
        border-color: #f0a500;
    }

    .sop-document p,
    .sop-document li { color: #222; }

    .sop-document strong { color: #c98a00; }
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 640px) {
    .hero { padding: 2rem 1rem; }
    .card { padding: 1.5rem; }
    .sop-document { padding: 1.5rem; }
    .action-buttons { flex-direction: column; align-items: stretch; }
    .action-buttons .btn-secondary,
    .action-buttons .btn-primary { justify-content: center; }
    .history-grid { grid-template-columns: 1fr; }
}