:root {
    --bg: #0a0a0f;
    --bg2: #111118;
    --bg3: #1a1a26;
    --border: #2a2a40;
    --border2: #3a3a55;
    --text: #e8e8f0;
    --text2: #9898b8;
    --text3: #6868a0;
    --accent: #7c6af7;
    --accent2: #a89bf5;
    --accent3: #4a3fa0;
    --green: #4ade80;
    --red: #f87171;
    --yellow: #fbbf24;
    --cyan: #67e8f9;
    --card-bg: #111118;
    --card-shadow: 0 4px 24px rgba(0,0,0,0.4);
    --input-bg: #0a0a0f;
    --tag-bg: #1e1e30;
    --result-bg: #0d1a0d;
    --result-border: #2a502a;
    --result-text: #4ade80;
    --step-bg: #13131f;
    --matrix-bg: #0f0f1a;
    --table-head-bg: #1e1e3a;
    --code-bg: #0a0a14;
    --shimmer: linear-gradient(90deg, transparent, rgba(124,106,247,0.1), transparent);
}

[data-theme="light"] {
    --bg: #f0f0f8;
    --bg2: #ffffff;
    --bg3: #e8e8f5;
    --border: #d0d0e8;
    --border2: #b8b8d8;
    --text: #1a1a2e;
    --text2: #4a4a6e;
    --text3: #7878a8;
    --accent: #5b4de8;
    --accent2: #7b6df8;
    --accent3: #dddaf8;
    --card-bg: #ffffff;
    --card-shadow: 0 4px 24px rgba(0,0,0,0.08);
    --input-bg: #f8f8ff;
    --tag-bg: #eeeef8;
    --result-bg: #f0fff0;
    --result-border: #86efac;
    --result-text: #166534;
    --step-bg: #f8f8ff;
    --matrix-bg: #f0f0fc;
    --table-head-bg: #e8e8f8;
    --code-bg: #f0f0fc;
}

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

body {
    font-family: 'Syne', sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    transition: background 0.3s, color 0.3s;
    overflow-x: hidden;
}

.grid-bg {
    position: fixed;
    inset: 0;
    background-image:
        linear-gradient(var(--border) 1px, transparent 1px),
        linear-gradient(90deg, var(--border) 1px, transparent 1px);
    background-size: 60px 60px;
    opacity: 0.3;
    pointer-events: none;
    z-index: 0;
}

/* ── Navbar ── */
.navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.875rem 2rem;
    background: var(--bg2);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(12px);
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    font-weight: 800;
    font-size: 1.2rem;
    color: var(--text);
    white-space: nowrap;
}
.logo-icon { font-size: 1.4rem; }
.accent { color: var(--accent); }

.nav-links {
    display: flex;
    gap: 0.25rem;
    flex: 1;
    justify-content: center;
    flex-wrap: wrap;
}

.nav-link {
    padding: 0.4rem 0.9rem;
    border-radius: 6px;
    text-decoration: none;
    color: var(--text2);
    font-size: 0.875rem;
    font-weight: 600;
    transition: all 0.2s;
    font-family: 'Space Mono', monospace;
}
.nav-link:hover { background: var(--bg3); color: var(--text); }
.nav-link.active { background: var(--accent3); color: var(--accent2); }

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

.theme-toggle {
    width: 36px; height: 36px;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--bg3);
    cursor: pointer;
    font-size: 1rem;
    display: flex; align-items: center; justify-content: center;
    transition: all 0.2s;
    color: var(--text);
}
.theme-toggle:hover { border-color: var(--accent); }

.history-btn {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.9rem;
    border-radius: 8px;
    border: 1px solid var(--border);
    background: var(--bg3);
    color: var(--text2);
    cursor: pointer;
    font-size: 0.875rem;
    font-family: 'Syne', sans-serif;
    font-weight: 600;
    transition: all 0.2s;
}
.history-btn:hover { border-color: var(--accent); color: var(--text); }

.history-mobile-btn {
    background: var(--accent3);
    color: var(--accent2);
    border: none;
    text-align: left;
    width: 100%;
    cursor: pointer;
}

@media (max-width: 900px) {
    .desktop-only { display: none !important; }
}
@media (min-width: 901px) {
    .mobile-only { display: none !important; }
}
.nav-mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text);
    cursor: pointer;
    font-size: 1.1rem;
    margin-left: auto;
}
@media (max-width: 900px) {
    .nav-mobile-toggle { display: block; }
}

.mobile-nav {
    display: none;
    flex-direction: column;
    background: var(--bg2);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem 1rem;
    position: sticky;
    top: 57px;
    z-index: 99;
}
.mobile-nav.open { display: flex; }
.mobile-nav-link {
    padding: 0.6rem 0.5rem;
    text-decoration: none;
    color: var(--text2);
    font-size: 0.9rem;
    font-weight: 600;
    border-bottom: 1px solid var(--border);
}
.mobile-nav-link:last-child { border-bottom: none; }

/* ── History Sidebar ── */
.history-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 200;
}
.history-overlay.open { display: block; }

.history-sidebar {
    position: fixed;
    right: -440px;
    top: 0;
    height: 100vh;
    width: 360px;
    background: var(--bg2);
    border-left: 1px solid var(--border);
    z-index: 201;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
    box-shadow: -10px 0 30px rgba(0,0,0,0.5);
    visibility: hidden;
    opacity: 0;
    pointer-events: none;
}
.history-sidebar.open {
    right: 0;
    visibility: visible;
    opacity: 1;
    pointer-events: auto;
}

.history-header {
    padding: 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.history-header h3 { font-size: 1rem; font-weight: 700; }
.history-actions { display: flex; gap: 0.5rem; }
.btn-clear {
    padding: 0.3rem 0.7rem;
    border-radius: 6px;
    border: 1px solid var(--red);
    background: none;
    color: var(--red);
    font-size: 0.8rem;
    cursor: pointer;
    font-family: 'Syne', sans-serif;
    transition: all 0.2s;
}
.btn-clear:hover { background: var(--red); color: white; }
.btn-close {
    padding: 0.3rem 0.7rem;
    border-radius: 6px;
    border: 1px solid var(--border);
    background: none;
    color: var(--text2);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s;
}
.btn-close:hover { border-color: var(--text); color: var(--text); }

.history-list { flex: 1; overflow-y: auto; padding: 0.75rem; }
.history-empty { text-align: center; color: var(--text3); padding: 2rem; font-size: 0.9rem; }

.history-item {
    padding: 0.875rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 0.75rem;
    background: var(--bg3);
    cursor: pointer;
    transition: border-color 0.2s;
}
.history-item:hover { border-color: var(--accent); }
.history-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.4rem;
}
.history-algo {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--accent2);
    font-family: 'Space Mono', monospace;
}
.history-time { font-size: 0.7rem; color: var(--text3); }
.history-mode {
    display: inline-block;
    font-size: 0.65rem;
    padding: 0.1rem 0.5rem;
    border-radius: 4px;
    background: var(--tag-bg);
    color: var(--text2);
    font-weight: 700;
    margin-bottom: 0.4rem;
}
.history-input, .history-output {
    font-size: 0.8rem;
    color: var(--text2);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    font-family: 'Space Mono', monospace;
}
.history-output { color: var(--green); }

/* ── Main Content ── */
.main-content {
    position: relative;
    z-index: 1;
    min-height: calc(100vh - 57px - 80px);
}

/* ── Hero (index page) ── */
.hero {
    padding: 5rem 2rem 3rem;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}
.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.35rem 1rem;
    border: 1px solid var(--border2);
    border-radius: 100px;
    font-size: 0.8rem;
    color: var(--text3);
    font-family: 'Space Mono', monospace;
    margin-bottom: 1.5rem;
    background: var(--bg3);
}
.hero h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1rem;
}
.hero h1 span { color: var(--accent); }
.hero p {
    font-size: 1.1rem;
    color: var(--text2);
    max-width: 600px;
    margin: 0 auto 2.5rem;
    line-height: 1.7;
}

.algo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.25rem;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.algo-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 1.75rem;
    text-decoration: none;
    color: inherit;
    display: block;
    transition: all 0.25s;
    position: relative;
    overflow: hidden;
}
.algo-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--accent) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.3s;
}
.algo-card:hover {
    border-color: var(--accent);
    transform: translateY(-3px);
    box-shadow: 0 8px 32px rgba(124,106,247,0.2);
}
.algo-card:hover::before { opacity: 0.05; }

.algo-card-icon { font-size: 2rem; margin-bottom: 1rem; }
.algo-card-num {
    font-size: 0.7rem;
    color: var(--text3);
    font-family: 'Space Mono', monospace;
    margin-bottom: 0.4rem;
}
.algo-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text);
}
.algo-card p { font-size: 0.875rem; color: var(--text2); line-height: 1.6; }
.algo-card-formula {
    margin-top: 1rem;
    padding: 0.6rem 0.8rem;
    background: var(--code-bg);
    border-radius: 6px;
    font-family: 'Space Mono', monospace;
    font-size: 0.8rem;
    color: var(--accent2);
    border: 1px solid var(--border);
}

/* ── Cipher Page Layout ── */
.cipher-page {
    max-width: 1300px;
    margin: 0 auto;
    padding: 2rem;
    display: grid;
    grid-template-columns: 420px 1fr;
    gap: 1.5rem;
    align-items: start;
}

.page-header {
    grid-column: 1 / -1;
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border);
}
.page-header-icon { font-size: 3rem; }
.page-header-title {
    font-size: clamp(1.5rem, 3vw, 2.2rem);
    font-weight: 800;
}
.page-header-subtitle { color: var(--text2); margin-top: 0.25rem; font-size: 0.95rem; }
.page-header-formula {
    margin-top: 0.75rem;
    display: inline-block;
    padding: 0.4rem 0.9rem;
    background: var(--code-bg);
    border: 1px solid var(--border2);
    border-radius: 6px;
    font-family: 'Space Mono', monospace;
    font-size: 0.85rem;
    color: var(--accent2);
}

/* ── Card ── */
.card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    overflow: hidden;
}
.card-header {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 0.95rem;
    background: var(--bg3);
}
.card-body { padding: 1.25rem; }

/* ── Form Elements ── */
.form-group { margin-bottom: 1rem; }
.form-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text2);
    margin-bottom: 0.4rem;
    font-family: 'Space Mono', monospace;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.form-input, .form-select, .form-textarea {
    width: 100%;
    padding: 0.7rem 0.9rem;
    background: var(--input-bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 0.9rem;
    font-family: 'Space Mono', monospace;
    transition: border-color 0.2s;
    outline: none;
}
.form-input:focus, .form-select:focus, .form-textarea:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(124,106,247,0.15);
}
.form-textarea { min-height: 100px; resize: vertical; }
.form-select { cursor: pointer; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; }
.form-hint { font-size: 0.75rem; color: var(--text3); margin-top: 0.3rem; }

/* ── Mode Toggle ── */
.mode-toggle {
    display: grid;
    grid-template-columns: 1fr 1fr;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 3px;
    margin-bottom: 1.25rem;
}
.mode-btn {
    padding: 0.55rem;
    border: none;
    background: none;
    border-radius: 6px;
    color: var(--text2);
    font-size: 0.875rem;
    font-family: 'Syne', sans-serif;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
}
.mode-btn.active { background: var(--accent); color: white; }

/* ── Submit Button ── */
.btn-submit {
    width: 100%;
    padding: 0.85rem;
    background: var(--accent);
    border: none;
    border-radius: 10px;
    color: white;
    font-size: 1rem;
    font-family: 'Syne', sans-serif;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 1.25rem;
}
.btn-submit:hover { background: var(--accent2); transform: translateY(-1px); box-shadow: 0 4px 16px rgba(124,106,247,0.4); }
.btn-submit:active { transform: translateY(0); }
.btn-submit.loading { opacity: 0.7; pointer-events: none; }

/* ── Result Box ── */
.result-box {
    padding: 1rem;
    background: var(--result-bg);
    border: 1px solid var(--result-border);
    border-radius: 10px;
    font-family: 'Space Mono', monospace;
    font-size: 1rem;
    color: var(--result-text);
    word-break: break-all;
    min-height: 52px;
    margin-top: 0.5rem;
    letter-spacing: 0.05em;
}
.result-placeholder { color: var(--text3); font-style: italic; font-size: 0.85rem; }

/* ── Steps Panel ── */
.steps-panel { display: flex; flex-direction: column; gap: 1rem; }

.step-card {
    background: var(--step-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    animation: stepIn 0.3s ease forwards;
}
@keyframes stepIn {
    from { opacity: 0; transform: translateY(20px) scale(0.98); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

.step-card {
    background: var(--step-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    opacity: 0;
    transition: all 0.4s ease;
}

.step-card.visible {
    animation: stepIn 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

/* Sticky card for Playfair Matrix */
@media (min-width: 901px) {
    .sticky-card {
        position: sticky;
        top: 80px;
        z-index: 100;
        box-shadow: 0 10px 30px rgba(0,0,0,0.5);
    }
}

.calculating-shimmer {
    position: relative;
    overflow: hidden;
}

.calculating-shimmer::after {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--shimmer);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

.result-box.new-result {
    animation: resultPop 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes resultPop {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); border-color: var(--green); box-shadow: 0 0 20px rgba(74, 222, 128, 0.3); }
    100% { transform: scale(1); }
}
.step-card-header {
    padding: 0.75rem 1rem;
    background: var(--table-head-bg);
    border-bottom: 1px solid var(--border);
    font-size: 0.85rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent2);
}
.step-card-body { padding: 1rem; }

/* Formula Block */
.formula-block {
    padding: 1rem 1.25rem;
    background: var(--code-bg);
    border: 1px solid var(--border2);
    border-radius: 8px;
    font-family: 'Space Mono', monospace;
    font-size: 1.1rem;
    color: var(--cyan);
    text-align: center;
    margin-bottom: 0.75rem;
    letter-spacing: 0.05em;
}
.formula-desc { font-size: 0.85rem; color: var(--text2); line-height: 1.6; }

/* Rules List */
.rules-list {
    padding-left: 1.25rem;
    color: var(--text2);
    font-size: 0.9rem;
    line-height: 1.6;
}
.rules-list li {
    margin-bottom: 0.5rem;
}
.rules-list li::marker {
    color: var(--accent);
}

/* ── Process Table ── */
.process-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.82rem;
    font-family: 'Space Mono', monospace;
}
.process-table th {
    padding: 0.6rem 0.75rem;
    background: var(--table-head-bg);
    border: 1px solid var(--border);
    color: var(--text2);
    font-weight: 700;
    text-align: left;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.process-table td {
    padding: 0.55rem 0.75rem;
    border: 1px solid var(--border);
    color: var(--text);
    vertical-align: middle;
}
.process-table tr { transition: all 0.2s; }
.process-table tr:hover td { background: var(--bg3); color: var(--accent2); }
.process-table tr.active td { background: var(--accent3); color: white; }
.cell-char {
    font-weight: 700;
    color: var(--cyan);
    font-size: 1rem;
}
.cell-formula { color: var(--yellow); }
.cell-result {
    font-weight: 700;
    color: var(--green);
    font-size: 1rem;
}
.cell-key { color: var(--accent2); }
.cell-skip { color: var(--text3); font-style: italic; }

/* ── Vigenère Recta ── */
.recta-container {
    overflow-x: auto;
    max-height: 400px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg2);
    position: relative;
}
.recta-table {
    border-collapse: collapse;
    font-family: 'Space Mono', monospace;
    font-size: 0.7rem;
    width: 100%;
}
.recta-table th, .recta-table td {
    width: 24px;
    height: 24px;
    text-align: center;
    border: 1px solid var(--border);
    padding: 0;
}
.recta-table th {
    background: var(--table-head-bg);
    color: var(--accent2);
    position: sticky;
    top: 0;
    z-index: 2;
}
.recta-table th:first-child {
    left: 0;
    z-index: 3;
}
.recta-table td:first-child {
    background: var(--table-head-bg);
    color: var(--accent2);
    position: sticky;
    left: 0;
    z-index: 1;
    font-weight: 700;
}
.recta-table tr:hover td { background: rgba(124,106,247,0.1); }
.recta-table td.highlight-col { background: rgba(124,106,247,0.15); }
.recta-table td.highlight-active { background: var(--accent) !important; color: white !important; font-weight: 700; box-shadow: inset 0 0 8px rgba(0,0,0,0.5); }

/* ── Matrix Display ── */
.matrix-container {
    display: flex;
    gap: 2rem;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
}
.matrix-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}
.matrix-label { font-size: 0.8rem; color: var(--text3); font-family: 'Space Mono', monospace; }
.matrix {
    display: inline-grid;
    gap: 3px;
    padding: 0.75rem;
    background: var(--matrix-bg);
    border: 2px solid var(--border2);
    border-radius: 8px;
    position: relative;
}
.matrix::before, .matrix::after {
    content: '';
    position: absolute;
    top: 4px;
    bottom: 4px;
    width: 3px;
    background: var(--border2);
    border-radius: 2px;
}
.matrix::before { left: 4px; }
.matrix::after { right: 4px; }
.matrix-cell {
    width: 42px;
    height: 42px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-family: 'Space Mono', monospace;
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--accent2);
}
.matrix-op {
    font-size: 1.5rem;
    color: var(--text3);
    font-weight: 300;
}

/* ── Playfair Matrix ── */
.playfair-matrix {
    display: grid;
    grid-template-columns: repeat(5, 44px);
    gap: 3px;
    margin: 0 auto;
}
.playfair-cell {
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 4px;
    font-family: 'Space Mono', monospace;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text);
    transition: all 0.2s;
}
.playfair-cell.key-letter { background: var(--accent3); color: var(--accent2); border-color: var(--accent); }
.playfair-cell.highlight-a { background: var(--green) !important; border-color: var(--green); color: var(--bg) !important; font-weight: 800; transform: scale(1.1); z-index: 5; box-shadow: 0 0 15px var(--green); }
.playfair-cell.highlight-b { background: var(--yellow) !important; border-color: var(--yellow); color: var(--bg) !important; font-weight: 800; transform: scale(1.1); z-index: 5; box-shadow: 0 0 15px var(--yellow); }
.playfair-cell.highlight-rect { background: rgba(103,232,249,0.2); border-color: var(--cyan); border-style: dashed; }
.playfair-cell.highlight-row { background: rgba(124,106,247,0.1); }
.playfair-cell.highlight-col { background: rgba(124,106,247,0.1); }

/* ── Pair Steps ── */
.pair-steps { display: flex; flex-direction: column; gap: 0.75rem; }
.pair-step {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.75rem 1rem;
    background: var(--bg3);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 0.85rem;
    font-family: 'Space Mono', monospace;
    flex-wrap: wrap;
}
.pair-chars {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--cyan);
    min-width: 50px;
}
.pair-rule {
    flex: 1;
    color: var(--yellow);
    font-size: 0.8rem;
}
.pair-arrow { color: var(--text3); }
.pair-result {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--green);
}

/* ── Result Step ── */
.result-step {
    display: grid;
    gap: 0.75rem;
}
.result-row { display: flex; flex-direction: column; gap: 0.25rem; }
.result-label { font-size: 0.75rem; color: var(--text3); font-family: 'Space Mono', monospace; text-transform: uppercase; }
.result-value {
    padding: 0.75rem 1rem;
    border-radius: 8px;
    font-family: 'Space Mono', monospace;
    font-size: 0.9rem;
    word-break: break-all;
    letter-spacing: 0.05em;
}
.result-value.plain { background: var(--bg3); border: 1px solid var(--border); color: var(--text); }
.result-value.cipher { background: var(--result-bg); border: 1px solid var(--result-border); color: var(--result-text); }

/* ── Matrix Input ── */
.matrix-input-grid { display: grid; gap: 4px; }
.matrix-input-cell {
    width: 60px;
    height: 42px;
    text-align: center;
    padding: 0.3rem;
    background: var(--input-bg);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text);
    font-family: 'Space Mono', monospace;
    font-size: 0.9rem;
    transition: border-color 0.2s;
    outline: none;
}
.matrix-input-cell:focus { border-color: var(--accent); }

/* ── Error ── */
.error-box {
    padding: 0.875rem 1rem;
    background: rgba(248,113,113,0.1);
    border: 1px solid var(--red);
    border-radius: 8px;
    color: var(--red);
    font-size: 0.875rem;
    margin-top: 0.75rem;
    display: none;
}
.error-box.show { display: block; }

/* ── Info block ── */
.info-block {
    padding: 0.75rem 1rem;
    background: rgba(124,106,247,0.1);
    border: 1px solid var(--accent3);
    border-radius: 8px;
    font-size: 0.85rem;
    color: var(--text2);
    margin-bottom: 0.75rem;
}
.info-block.success { background: rgba(74,222,128,0.1); border-color: var(--green); color: var(--green); }
.info-block.warning { background: rgba(251,191,36,0.1); border-color: var(--yellow); color: var(--yellow); }

/* ── Footer ── */
.footer {
    border-top: 1px solid var(--border);
    padding: 1.5rem 2rem;
    text-align: center;
    color: var(--text3);
    font-size: 0.8rem;
    position: relative;
    z-index: 1;
}
.footer-sub { margin-top: 0.25rem; font-family: 'Space Mono', monospace; font-size: 0.75rem; }

/* ── Scrollbar ── */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg2); }
::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 3px; }

/* ── Responsive ── */
@media (max-width: 900px) {
    .cipher-page { grid-template-columns: 1fr; padding: 1rem; }
    .nav-links { display: none; }
    .nav-mobile-toggle { display: block; }
    .nav-actions .history-btn span:last-child { display: none; }
}
@media (max-width: 600px) {
    .page-header { flex-direction: column; gap: 0.75rem; }
    .algo-grid { grid-template-columns: 1fr; padding: 1rem; }
    .history-sidebar { width: 100%; }
    .form-row { grid-template-columns: 1fr; }
    
    /* Matrices in steps */
    .matrix-container { gap: 1rem; }
    .matrix-op { font-size: 1.2rem; }
    .matrix-cell { width: 36px; height: 36px; font-size: 0.8rem; }
    .matrix { padding: 0.5rem; }
    
    /* Hill block calc */
    .hill-block-calc { padding: 0.75rem; }
    .hill-calc-row { font-size: 0.75rem; }
    
    /* Playfair pairs */
    .pair-step { gap: 0.5rem; padding: 0.6rem; }
    .pair-chars, .pair-result { font-size: 1rem; min-width: 40px; }
    .pair-rule { font-size: 0.75rem; }
}

/* Documentation Content Styling */
.docs-content {
    background: linear-gradient(to bottom, var(--bg2), var(--bg));
}
.code-block {
    font-family: 'Space Mono', monospace;
    color: var(--cyan);
    border: 1px solid var(--border);
    box-shadow: inset 0 0 10px rgba(0,0,0,0.2);
}


/* ── Loading spinner ── */
@keyframes spin { to { transform: rotate(360deg); } }
.spinner {
    width: 16px; height: 16px;
    border: 2px solid rgba(255,255,255,0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

/* Hill block calc */
.hill-block-calc {
    padding: 1rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg3);
    margin-bottom: 0.75rem;
}
.hill-block-header {
    font-size: 0.8rem;
    color: var(--text3);
    font-family: 'Space Mono', monospace;
    margin-bottom: 0.75rem;
    font-weight: 700;
}
.hill-calc-row {
    font-family: 'Space Mono', monospace;
    font-size: 0.8rem;
    color: var(--text2);
    padding: 0.3rem 0;
    border-bottom: 1px dashed var(--border);
}
.hill-calc-row:last-child { border-bottom: none; }
.hill-result-chars {
    margin-top: 0.5rem;
    font-family: 'Space Mono', monospace;
    font-size: 0.9rem;
    color: var(--green);
    font-weight: 700;
}

.size-selector { display: flex; gap: 0.5rem; margin-bottom: 0.75rem; }
.size-btn {
    flex: 1;
    padding: 0.5rem;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg3);
    color: var(--text2);
    font-family: 'Syne', sans-serif;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.875rem;
}
.size-btn.active { border-color: var(--accent); color: var(--accent2); background: var(--accent3); }