/* ── Google Fonts ─────────────────────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

/* ── CSS Variables ────────────────────────────────────────────────────────── */
:root {
    --bg:              #080d18;
    --bg-panel:        #0d1426;
    --bg-card:         #111d35;
    --bg-input:        #0a1020;
    --border:          #1e3358;
    --border-light:    #2a4a7a;
    --primary:         #3b82f6;
    --primary-hover:   #2563eb;
    --primary-glow:    rgba(59,130,246,0.25);
    --secondary:       #8b5cf6;
    --secondary-glow:  rgba(139,92,246,0.25);
    --success:         #10b981;
    --success-glow:    rgba(16,185,129,0.2);
    --warning:         #f59e0b;
    --danger:          #ef4444;
    --danger-glow:     rgba(239,68,68,0.2);
    --text:            #e2e8f0;
    --text-muted:      #64748b;
    --text-code:       #7dd3fc;
    --enc-bg:          #05101f;
    --enc-border:      #1d4ed8;
    --enc-text:        #60a5fa;
    --enc-label:       #f59e0b;
}

/* ── Reset ────────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    font-family: 'Inter', sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.6;
}

/* ── Navigation ───────────────────────────────────────────────────────────── */
.nav {
    background: var(--bg-panel);
    border-bottom: 1px solid var(--border);
    padding: 0 2rem;
    display: flex;
    align-items: center;
    height: 56px;
    gap: 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(8px);
}
.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--primary);
    text-decoration: none;
    letter-spacing: -0.02em;
}
.nav-brand .lock-icon { font-size: 1.2rem; }
.nav-links { display: flex; gap: 0.25rem; margin-left: auto; }
.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.875rem;
    padding: 0.35rem 0.75rem;
    border-radius: 6px;
    transition: all 0.2s;
    font-weight: 500;
}
.nav-link:hover, .nav-link.active {
    color: var(--text);
    background: var(--bg-card);
}

/* ── Layout ───────────────────────────────────────────────────────────────── */
.container { max-width: 1280px; margin: 0 auto; padding: 2rem; }
.page-header { margin-bottom: 2rem; }
.page-title {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.page-subtitle { color: var(--text-muted); font-size: 0.9rem; margin-top: 0.25rem; }

/* ── Tabs ─────────────────────────────────────────────────────────────────── */
.tabs { display: flex; border-bottom: 1px solid var(--border); margin-bottom: 2rem; }
.tab-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.75rem 1.25rem;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    transition: all 0.2s;
    font-family: 'Inter', sans-serif;
}
.tab-btn:hover { color: var(--text); }
.tab-btn.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ── Cards ────────────────────────────────────────────────────────────────── */
.card {
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
}
.card-title {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* ── Form elements ────────────────────────────────────────────────────────── */
.form-group { margin-bottom: 1.25rem; }
.form-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    margin-bottom: 0.4rem;
}
.form-input, .form-textarea {
    width: 100%;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.65rem 0.85rem;
    color: var(--text);
    font-size: 0.9rem;
    font-family: 'Inter', sans-serif;
    transition: border-color 0.2s, box-shadow 0.2s;
    outline: none;
}
.form-input:focus, .form-textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}
.form-input::placeholder, .form-textarea::placeholder { color: var(--text-muted); }
.form-input[readonly] { opacity: 0.7; cursor: default; }
.form-textarea { min-height: 90px; resize: vertical; }

.form-hint {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.3rem;
}

/* ── Buttons ──────────────────────────────────────────────────────────────── */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.6rem 1.25rem;
    border: none;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    font-family: 'Inter', sans-serif;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
}
.btn:disabled { opacity: 0.4; cursor: not-allowed; }
.btn-primary {
    background: var(--primary);
    color: #fff;
}
.btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
    box-shadow: 0 0 16px var(--primary-glow);
}
.btn-secondary {
    background: var(--secondary);
    color: #fff;
}
.btn-secondary:hover:not(:disabled) {
    background: #7c3aed;
    box-shadow: 0 0 16px var(--secondary-glow);
}
.btn-success {
    background: var(--success);
    color: #fff;
}
.btn-success:hover:not(:disabled) { background: #059669; }
.btn-danger {
    background: var(--danger);
    color: #fff;
}
.btn-danger:hover:not(:disabled) { background: #dc2626; }
.btn-ghost {
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text);
}
.btn-ghost:hover:not(:disabled) { border-color: var(--border-light); }
.btn-sm { padding: 0.4rem 0.85rem; font-size: 0.8rem; }
.btn-group { display: flex; gap: 0.5rem; flex-wrap: wrap; margin-top: 1rem; }

/* ── Status messages ──────────────────────────────────────────────────────── */
.status {
    margin-top: 1rem;
    padding: 0.65rem 1rem;
    border-radius: 8px;
    font-size: 0.875rem;
    font-weight: 500;
    display: none;
    align-items: center;
    gap: 0.5rem;
}
.status.show { display: flex; }
.status-info  { background: rgba(59,130,246,0.12); border: 1px solid rgba(59,130,246,0.3); color: #93c5fd; }
.status-success { background: rgba(16,185,129,0.12); border: 1px solid rgba(16,185,129,0.3); color: #6ee7b7; }
.status-error { background: rgba(239,68,68,0.12); border: 1px solid rgba(239,68,68,0.3); color: #fca5a5; }
.status-loading { background: rgba(245,158,11,0.12); border: 1px solid rgba(245,158,11,0.3); color: #fcd34d; }

/* ── Encrypted value display ─────────────────────────────────────────────── */
.enc-value {
    background: var(--enc-bg);
    border: 1px solid var(--enc-border);
    border-radius: 8px;
    padding: 0.65rem 0.85rem;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.75rem;
    color: var(--enc-text);
    word-break: break-all;
    line-height: 1.5;
}
.enc-label {
    color: var(--enc-label);
    font-weight: 600;
}
.enc-hint { color: var(--text-muted); font-size: 0.75rem; margin-top: 0.3rem; }

/* ── Split pane layout ────────────────────────────────────────────────────── */
.split-pane {
    display: grid;
    grid-template-columns: 360px 1fr;
    gap: 1.5rem;
    align-items: start;
}
@media (max-width: 900px) {
    .split-pane { grid-template-columns: 1fr; }
}

/* ── Record list ──────────────────────────────────────────────────────────── */
.record-list { display: flex; flex-direction: column; gap: 0.5rem; }
.record-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    cursor: pointer;
    transition: all 0.2s;
}
.record-item:hover { border-color: var(--border-light); }
.record-item.selected {
    border-color: var(--primary);
    background: rgba(59,130,246,0.08);
}
.record-item-serial {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    color: var(--primary);
    font-weight: 500;
}
.record-item-meta {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.2rem;
}

/* ── Password box ─────────────────────────────────────────────────────────── */
.password-box {
    background: rgba(245,158,11,0.06);
    border: 1px solid rgba(245,158,11,0.25);
    border-radius: 10px;
    padding: 1rem 1.25rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}
.password-box .form-label { margin-bottom: 0; color: #fbbf24; }
.password-box .form-input { flex: 1; min-width: 180px; }
.password-hint {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
    font-family: 'JetBrains Mono', monospace;
}

/* ── Info/hint blocks ─────────────────────────────────────────────────────── */
.info-block {
    background: rgba(59,130,246,0.06);
    border: 1px dashed rgba(59,130,246,0.3);
    border-radius: 8px;
    padding: 0.75rem 1rem;
    font-size: 0.825rem;
    color: #93c5fd;
    margin-bottom: 1.25rem;
}
.info-block strong { color: var(--primary); }

/* ── Spinner ──────────────────────────────────────────────────────────────── */
.spinner {
    display: inline-block;
    width: 14px; height: 14px;
    border: 2px solid rgba(255,255,255,0.2);
    border-top-color: currentColor;
    border-radius: 50%;
    animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Divider ──────────────────────────────────────────────────────────────── */
.divider {
    border: none;
    border-top: 1px solid var(--border);
    margin: 1.5rem 0;
}

/* ── Badge ────────────────────────────────────────────────────────────────── */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
    padding: 0.2rem 0.55rem;
    border-radius: 20px;
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}
.badge-enc { background: rgba(29,78,216,0.2); color: #93c5fd; border: 1px solid rgba(29,78,216,0.4); }
.badge-plain { background: rgba(16,185,129,0.2); color: #6ee7b7; border: 1px solid rgba(16,185,129,0.4); }

/* ── Index page specifics ─────────────────────────────────────────────────── */
.hero {
    text-align: center;
    padding: 3rem 1rem;
    background: radial-gradient(ellipse at 50% 0%, rgba(59,130,246,0.08) 0%, transparent 60%);
    border-bottom: 1px solid var(--border);
    margin-bottom: 2rem;
}
.hero-title {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.04em;
    background: linear-gradient(135deg, #60a5fa, #a78bfa, #34d399);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.75rem;
}
.hero-sub {
    color: var(--text-muted);
    font-size: 1rem;
    max-width: 520px;
    margin: 0 auto;
}
.hero-warning {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: 1.25rem;
    padding: 0.5rem 1rem;
    background: rgba(245,158,11,0.1);
    border: 1px solid rgba(245,158,11,0.3);
    border-radius: 20px;
    font-size: 0.8rem;
    color: #fbbf24;
}

.demo-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 1.5rem;
}
@media (max-width: 700px) { .demo-grid { grid-template-columns: 1fr; } }

.demo-card {
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 1.75rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}
.demo-card:hover {
    border-color: var(--border-light);
    box-shadow: 0 4px 24px rgba(0,0,0,0.4);
}
.demo-card-icon { font-size: 2.5rem; margin-bottom: 0.75rem; }
.demo-card-title {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
}
.demo-card-desc { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 1.25rem; }
.demo-links { display: flex; gap: 0.5rem; flex-wrap: wrap; }

/* ── SVG Diagram ──────────────────────────────────────────────────────────── */
.diagram-wrap {
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    overflow-x: auto;
}
.diagram-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
}

/* ── Scrollbar ────────────────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-light); }

/* ── Decrypted result field ───────────────────────────────────────────────── */
.decrypted-section {
    background: rgba(16,185,129,0.06);
    border: 1px solid rgba(16,185,129,0.25);
    border-radius: 10px;
    padding: 1rem;
    margin-top: 1rem;
}
.decrypted-section .section-label {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--success);
    margin-bottom: 0.5rem;
}

/* ── Empty state ──────────────────────────────────────────────────────────── */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-muted);
    font-size: 0.875rem;
}
.empty-state .empty-icon { font-size: 2.5rem; margin-bottom: 0.75rem; }

/* ── Utilities ────────────────────────────────────────────────────────────── */
.mono { font-family: 'JetBrains Mono', monospace; }
.text-muted { color: var(--text-muted); }
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }
.text-primary { color: var(--primary); }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.flex { display: flex; }
.items-center { align-items: center; }
.gap-2 { gap: 0.5rem; }
.w-full { width: 100%; }