/* ── Reset & Base ── */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg: #0a0a0f;
    --surface: #13131a;
    --surface-hover: #1a1a24;
    --border: rgba(255, 255, 255, 0.06);
    --border-focus: rgba(139, 92, 246, 0.4);
    --text: #e4e4e7;
    --text-dim: #71717a;
    --text-faint: #52525b;
    --accent: #8b5cf6;
    --accent-glow: rgba(139, 92, 246, 0.15);
    --accent-soft: rgba(139, 92, 246, 0.08);
    --green: #34d399;
    --green-glow: rgba(52, 211, 153, 0.15);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    background: var(--bg);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 60px 20px 40px;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ── Noise Texture Overlay ── */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    opacity: 0.025;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
    background-repeat: repeat;
    background-size: 256px 256px;
}

/* ── Dot Grid ── */
body::after {
    content: '';
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    opacity: 0.03;
    background-image: radial-gradient(circle, rgba(255, 255, 255, 0.5) 1px, transparent 1px);
    background-size: 32px 32px;
}

/* ── Background Glows ── */
.glow {
    position: fixed;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.4;
    pointer-events: none;
    z-index: 0;
    animation: glowDrift 20s ease-in-out infinite alternate;
}

.glow-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.14), transparent 70%);
    top: -100px;
    left: -100px;
}

.glow-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.1), transparent 70%);
    bottom: -50px;
    right: -50px;
    animation-delay: -10s;
}

.glow-3 {
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, rgba(168, 85, 247, 0.08), transparent 70%);
    top: 50%;
    right: -80px;
    animation-delay: -5s;
    animation-duration: 25s;
}

@keyframes glowDrift {
    0% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(30px, 20px) scale(1.1); }
    100% { transform: translate(-20px, 40px) scale(0.95); }
}

/* ── Container ── */
.container {
    width: 100%;
    max-width: 780px;
    position: relative;
    z-index: 1;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ── Header ── */
.header {
    text-align: center;
    margin-bottom: 36px;
}

.title {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    background: linear-gradient(
        90deg,
        #e4e4e7 0%,
        #c4b5fd 25%,
        #e4e4e7 50%,
        #a78bfa 75%,
        #e4e4e7 100%
    );
    background-size: 200% 100%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.1s both,
               titleShimmer 8s ease-in-out infinite;
}

@keyframes titleShimmer {
    0%, 100% { background-position: 0% center; }
    50% { background-position: 100% center; }
}

.subtitle {
    color: var(--text-dim);
    font-size: 0.9rem;
    margin-top: 6px;
    font-weight: 400;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.2s both;
}

/* ── Try It Button ── */
.try-btn {
    display: inline-block;
    margin-top: 14px;
    padding: 8px 20px;
    border: 1px solid var(--border-focus);
    background: var(--accent-soft);
    color: var(--accent);
    font-size: 0.82rem;
    font-weight: 500;
    font-family: inherit;
    border-radius: 20px;
    cursor: pointer;
    transition: var(--transition);
    transition-property: background, border-color, transform, box-shadow;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.25s both;
}

.try-btn:hover {
    background: rgba(139, 92, 246, 0.15);
    box-shadow: 0 0 20px var(--accent-glow);
}

.try-btn:active {
    transform: scale(0.96);
}

.try-btn.hidden {
    opacity: 0;
    pointer-events: none;
    transform: scale(0.9);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

/* ── Method Selector ── */
.method-selector {
    margin-bottom: 14px;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.3s both;
}

.method-track {
    display: flex;
    position: relative;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 4px;
    gap: 2px;
}

.method-pill {
    position: absolute;
    top: 4px;
    left: 4px;
    height: calc(100% - 8px);
    border-radius: 7px;
    background: var(--accent-soft);
    border: 1px solid var(--border-focus);
    transition: var(--transition);
    transition-property: left, width;
    pointer-events: none;
    z-index: 0;
}

.method-btn {
    flex: 1;
    position: relative;
    z-index: 1;
    padding: 10px 12px;
    border: none;
    background: none;
    color: var(--text-dim);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 7px;
    transition: color var(--transition);
    font-family: inherit;
    white-space: nowrap;
}

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

.method-btn.active {
    color: var(--accent);
}

/* ── Method Description Row ── */
.method-info-row {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    margin-bottom: 6px;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.35s both;
}

.method-description {
    text-align: center;
    color: var(--text-faint);
    font-size: 0.78rem;
    min-height: 1.4em;
    transition: opacity 0.2s ease;
}

.method-description.fading {
    opacity: 0;
}

/* ── Info Toggle ── */
.info-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 22px;
    border: none;
    background: none;
    color: var(--text-faint);
    cursor: pointer;
    border-radius: 50%;
    transition: color var(--transition), background var(--transition);
    flex-shrink: 0;
}

.info-toggle:hover {
    color: var(--accent);
    background: var(--accent-soft);
}

.info-toggle.active {
    color: var(--accent);
}

/* ── Method Detail Card ── */
.method-detail {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.4s cubic-bezier(0.4, 0, 0.2, 1),
                margin 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    margin-bottom: 0;
}

.method-detail.open {
    grid-template-rows: 1fr;
    margin-bottom: 12px;
}

.method-detail-inner {
    overflow: hidden;
}

.method-detail.open .method-detail-inner {
    padding: 14px 18px;
    background: rgba(19, 19, 26, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
}

.method-detail-inner {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: 0 18px;
    transition: padding 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.detail-row {
    display: flex;
    align-items: center;
    gap: 12px;
}

.detail-label {
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-faint);
    min-width: 62px;
    flex-shrink: 0;
}

.detail-value {
    font-size: 0.8rem;
    color: var(--text-dim);
}

/* Coverage bar */
.detail-coverage {
    display: flex;
    align-items: center;
    gap: 10px;
    flex: 1;
}

.coverage-bar {
    flex: 1;
    height: 4px;
    background: rgba(255, 255, 255, 0.04);
    border-radius: 2px;
    overflow: hidden;
    max-width: 140px;
}

.coverage-fill {
    height: 100%;
    background: var(--accent);
    border-radius: 2px;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Example */
.detail-example {
    display: flex;
    align-items: center;
    gap: 8px;
}

.example-before {
    color: var(--text-faint);
}

.example-arrow {
    color: var(--text-faint);
    font-size: 0.7rem;
}

.example-after {
    color: var(--accent);
}

/* ── Converter ── */
.converter {
    display: flex;
    gap: 0;
    align-items: stretch;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.4s both;
}

/* ── Panels ── */
.panel {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    position: relative;
    transition: border-color var(--transition), box-shadow var(--transition), transform var(--transition);
}

/* Animated gradient border glow */
.panel::before {
    content: '';
    position: absolute;
    inset: -1px;
    border-radius: inherit;
    padding: 1px;
    background: conic-gradient(
        from var(--border-angle, 0deg),
        transparent 40%,
        rgba(139, 92, 246, 0.3) 50%,
        transparent 60%
    );
    -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    opacity: 0;
    transition: opacity 0.5s ease;
    animation: rotateBorder 4s linear infinite;
    pointer-events: none;
    z-index: 1;
}

.panel:focus-within::before {
    opacity: 1;
}

.panel:focus-within {
    border-color: transparent;
    box-shadow: 0 0 24px var(--accent-glow), 0 8px 32px rgba(0, 0, 0, 0.3);
}

.output-panel:focus-within::before {
    background: conic-gradient(
        from var(--border-angle, 0deg),
        transparent 40%,
        rgba(52, 211, 153, 0.3) 50%,
        transparent 60%
    );
}

.output-panel:focus-within {
    border-color: transparent;
    box-shadow: 0 0 24px var(--green-glow), 0 8px 32px rgba(0, 0, 0, 0.3);
}

@keyframes rotateBorder {
    to { --border-angle: 360deg; }
}

@property --border-angle {
    syntax: "<angle>";
    initial-value: 0deg;
    inherits: false;
}

.panel-label {
    display: block;
    padding: 14px 16px 0;
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-faint);
}

/* ── Shared text area styles ── */
.text-area {
    flex: 1;
    width: 100%;
    min-height: 180px;
    padding: 10px 16px 16px;
    border: none;
    background: none;
    color: var(--text);
    font-size: 0.95rem;
    font-family: inherit;
    line-height: 1.6;
    resize: none;
    outline: none;
}

/* ── Custom Editor (input side) ── */
.editor {
    position: relative;
    flex: 1;
    min-height: 180px;
    cursor: text;
}

.editor-display {
    position: relative;
    padding: 10px 16px 16px;
    color: var(--text);
    font-size: 0.95rem;
    font-family: inherit;
    line-height: 1.6;
    white-space: pre-wrap;
    word-break: break-word;
    min-height: 180px;
    z-index: 1;
    pointer-events: none;
}

.editor-input {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    padding: 10px 16px 16px;
    font-size: 0.95rem;
    font-family: inherit;
    line-height: 1.6;
    border: none;
    background: transparent;
    color: transparent;
    caret-color: transparent;
    resize: none;
    outline: none;
    z-index: 2;
    overflow: hidden;
}

/* ── Custom Caret ── */
.editor-caret {
    position: absolute;
    top: 0;
    left: 0;
    width: 2px;
    height: 1.2em;
    background: var(--accent);
    border-radius: 1px;
    z-index: 3;
    pointer-events: none;
    opacity: 0;
    transition: transform 0.12s cubic-bezier(0.33, 1, 0.68, 1);
    will-change: transform;
}

.editor-caret.visible {
    animation: caretPulse 1s ease-in-out infinite;
}

.editor-caret.solid {
    animation: none;
    opacity: 1;
}

@keyframes caretPulse {
    0%, 30% { opacity: 1; }
    50%, 80% { opacity: 0; }
    100% { opacity: 1; }
}

/* ── Placeholders ── */
.placeholder {
    color: var(--text-faint);
    pointer-events: none;
}

/* ── Character spans (both sides) ── */
.ch {
    opacity: 1;
}

.ch.fresh {
    animation: charFade 0.18s ease-out both;
}

@keyframes charFade {
    from { opacity: 0; }
    to   { opacity: 1; }
}

/* ── Output Display ── */
.output-display {
    overflow-y: auto;
    white-space: pre-wrap;
    word-break: break-word;
    cursor: default;
    user-select: text;
}

/* ── Panel Footer ── */
.panel-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 10px 10px 16px;
    border-top: 1px solid var(--border);
}

.footer-actions {
    display: flex;
    gap: 4px;
}

.char-count {
    font-size: 0.75rem;
    color: var(--text-faint);
    font-variant-numeric: tabular-nums;
    transition: color var(--transition-fast);
}

/* ── Divider Arrow ── */
.divider {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 8px;
    flex-shrink: 0;
}

.arrow-icon {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--text-dim);
    transition: var(--transition);
    transition-property: color, border-color, transform;
}

.arrow-icon:hover {
    color: var(--accent);
    border-color: var(--border-focus);
}

/* ── Buttons ── */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 14px;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-dim);
    font-size: 0.78rem;
    font-weight: 500;
    font-family: inherit;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    transition-property: color, background, border-color, transform, box-shadow;
}

.btn:hover {
    color: var(--text);
    background: var(--surface-hover);
    border-color: rgba(255, 255, 255, 0.1);
}

.btn:active {
    transform: scale(0.96);
}

.btn-icon {
    padding: 7px 8px;
}

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

/* Clear button hover */
#clearBtn:hover {
    color: #f87171;
    border-color: rgba(248, 113, 113, 0.2);
    background: rgba(248, 113, 113, 0.06);
}

/* Paste button hover */
#pasteBtn:hover {
    color: var(--accent);
    border-color: var(--border-focus);
    background: var(--accent-soft);
}

/* ── Copy Button States ── */
.btn-copy {
    position: relative;
    gap: 0;
    transition: var(--transition);
    transition-property: color, background, border-color, transform, box-shadow, gap;
}

.btn-copy:hover {
    gap: 6px;
}

.btn-copy .check-icon {
    display: none;
}

.btn-copy.copied {
    color: var(--green);
    border-color: rgba(52, 211, 153, 0.3);
    background: rgba(52, 211, 153, 0.06);
    animation: copyPulse 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.btn-copy.copied .copy-icon {
    display: none;
}

.btn-copy.copied .check-icon {
    display: block;
}

@keyframes copyPulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.08); }
    100% { transform: scale(1); }
}

/* ── Keyboard Shortcut Hint ── */
.shortcut-hint {
    display: inline-flex;
    align-items: center;
    overflow: hidden;
    max-width: 0;
    padding: 0;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid transparent;
    font-size: 0.65rem;
    font-family: inherit;
    color: var(--text-faint);
    line-height: 1;
    white-space: nowrap;
    opacity: 0;
    transition: max-width 0.35s cubic-bezier(0.4, 0, 0.2, 1),
                padding 0.35s cubic-bezier(0.4, 0, 0.2, 1),
                opacity 0.25s ease,
                border-color 0.35s ease;
}

.btn-copy:hover .shortcut-hint {
    max-width: 80px;
    padding: 2px 6px;
    opacity: 1;
    border-color: rgba(255, 255, 255, 0.08);
}

.btn-copy.copied .shortcut-hint {
    max-width: 0;
    padding: 0;
    opacity: 0;
    border-color: transparent;
}

/* ── Info Bar ── */
.info-bar {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-top: 16px;
    padding: 12px;
    background: rgba(19, 19, 26, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.45s both;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.info-bar:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    border-color: rgba(255, 255, 255, 0.08);
}

.info-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.info-label {
    font-size: 0.75rem;
    color: var(--text-faint);
}

.info-value {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-dim);
    font-variant-numeric: tabular-nums;
    transition: color var(--transition-fast);
}

.info-value.has-value {
    color: var(--accent);
}

.info-divider {
    width: 1px;
    height: 16px;
    background: var(--border);
}

/* ── Character Map ── */
.charmap {
    margin-top: 16px;
    background: rgba(19, 19, 26, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    overflow: hidden;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.5s both;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.charmap:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    border-color: rgba(255, 255, 255, 0.08);
}

.charmap-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 12px 16px;
    border: none;
    background: none;
    color: var(--text-dim);
    font-size: 0.8rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: color var(--transition);
}

.charmap-toggle:hover {
    color: var(--text);
}

.charmap-arrow {
    transition: transform var(--transition);
}

.charmap.open .charmap-arrow {
    transform: rotate(180deg);
}

.charmap-body {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.charmap.open .charmap-body {
    grid-template-rows: 1fr;
}

.charmap-grid {
    overflow: hidden;
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding: 0 16px;
    transition: padding 0.35s ease;
}

.charmap.open .charmap-grid {
    padding: 0 16px 14px;
}

.charmap-item {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.78rem;
    color: var(--text-dim);
    animation: charFade 0.2s ease-out both;
}

.charmap-item .from {
    color: var(--text-faint);
}

.charmap-item .arrow {
    color: var(--text-faint);
    font-size: 0.65rem;
}

.charmap-item .to {
    color: var(--accent);
}

/* ── Shared collapsible panel style ── */
.compare, .history, .faq {
    margin-top: 10px;
    background: rgba(19, 19, 26, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.compare:hover, .history:hover, .faq:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    border-color: rgba(255, 255, 255, 0.08);
}

.compare-toggle, .history-toggle, .faq-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 12px 16px;
    border: none;
    background: none;
    color: var(--text-dim);
    font-size: 0.8rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: color var(--transition);
}

.compare-toggle:hover, .history-toggle:hover, .faq-toggle:hover {
    color: var(--text);
}

.compare-arrow, .history-arrow, .faq-arrow {
    transition: transform var(--transition);
}

.compare.open .compare-arrow,
.history.open .history-arrow,
.faq.open .faq-arrow {
    transform: rotate(180deg);
}

.compare-body, .history-body, .faq-body {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.compare.open .compare-body,
.history.open .history-body,
.faq.open .faq-body {
    grid-template-rows: 1fr;
}

/* ── Compare Mode ── */
.compare-grid {
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 8px;
    padding: 0 16px;
    transition: padding 0.35s ease;
}

.compare.open .compare-grid {
    padding: 0 16px 14px;
}

.compare-row {
    display: flex;
    align-items: baseline;
    gap: 12px;
    padding: 8px 12px;
    background: rgba(255, 255, 255, 0.015);
    border: 1px solid var(--border);
    border-radius: 8px;
}

.compare-method {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-faint);
    min-width: 72px;
    flex-shrink: 0;
}

.compare-result {
    font-size: 0.85rem;
    color: var(--text-dim);
    word-break: break-word;
    line-height: 1.5;
}

.compare-row:hover .compare-result {
    color: var(--text);
}

.compare-copy {
    margin-left: auto;
    padding: 4px 8px;
    border: 1px solid var(--border);
    background: none;
    color: var(--text-faint);
    font-size: 0.68rem;
    font-family: inherit;
    border-radius: 5px;
    cursor: pointer;
    flex-shrink: 0;
    transition: var(--transition);
    transition-property: color, border-color, background;
}

.compare-copy:hover {
    color: var(--accent);
    border-color: var(--border-focus);
    background: var(--accent-soft);
}

/* ── History ── */
.history-list {
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 0 16px;
    transition: padding 0.35s ease;
}

.history.open .history-list {
    padding: 0 16px 14px;
}

.history-empty {
    font-size: 0.78rem;
    color: var(--text-faint);
    padding: 4px 0;
}

.history-entry {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    background: rgba(255, 255, 255, 0.015);
    border: 1px solid var(--border);
    border-radius: 8px;
    cursor: pointer;
    transition: border-color var(--transition);
}

.history-entry:hover {
    border-color: var(--border-focus);
}

.history-text {
    font-size: 0.8rem;
    color: var(--text-dim);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    flex: 1;
    min-width: 0;
}

.history-method {
    font-size: 0.65rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--accent);
    background: var(--accent-soft);
    padding: 2px 7px;
    border-radius: 4px;
    flex-shrink: 0;
}

.history-clear {
    padding: 4px 10px;
    border: 1px solid var(--border);
    background: none;
    color: var(--text-faint);
    font-size: 0.7rem;
    font-family: inherit;
    border-radius: 5px;
    cursor: pointer;
    transition: var(--transition);
    transition-property: color, border-color;
}

.history-clear:hover {
    color: #f87171;
    border-color: rgba(248, 113, 113, 0.3);
}

/* ── FAQ ── */
.faq-list {
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 0 16px;
    transition: padding 0.35s ease;
}

.faq.open .faq-list {
    padding: 0 16px 14px;
}

.faq-item {
    border-radius: 6px;
}

.faq-question {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    padding: 10px 12px;
    border: none;
    background: none;
    font-size: 0.8rem;
    font-weight: 500;
    font-family: inherit;
    color: var(--text-dim);
    cursor: pointer;
    border-radius: 6px;
    text-align: left;
    transition: color var(--transition), background var(--transition);
}

.faq-question:hover {
    color: var(--text);
    background: rgba(255, 255, 255, 0.02);
}

.faq-icon {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    color: var(--text-faint);
    transition: transform 0.35s cubic-bezier(0.4, 0, 0.2, 1), color var(--transition);
}

.faq-item.open .faq-icon {
    transform: rotate(45deg);
    color: var(--accent);
}

.faq-answer {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.faq-item.open .faq-answer {
    grid-template-rows: 1fr;
}

.faq-answer p {
    overflow: hidden;
    padding: 0 12px 0 36px;
    font-size: 0.78rem;
    color: var(--text-faint);
    line-height: 1.6;
    transition: padding-bottom 0.35s ease;
}

.faq-item.open .faq-answer p {
    padding-bottom: 10px;
}

/* ── Share Button ── */
#shareBtn:hover {
    color: var(--accent);
    border-color: var(--border-focus);
    background: var(--accent-soft);
}

/* ── Toast ── */
.toast {
    position: fixed;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    padding: 10px 20px;
    background: var(--surface);
    border: 1px solid var(--border-focus);
    border-radius: 10px;
    color: var(--text);
    font-size: 0.82rem;
    font-weight: 500;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4), 0 0 20px var(--accent-glow);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    z-index: 100;
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ── SEO Content ── */
.seo-content {
    margin-top: 28px;
    padding: 20px;
    background: rgba(19, 19, 26, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.55s both;
    transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.seo-content:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
    border-color: rgba(255, 255, 255, 0.08);
}

.seo-content h2 {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-dim);
    margin-bottom: 8px;
}

.seo-content p {
    font-size: 0.78rem;
    color: var(--text-faint);
    line-height: 1.7;
}

/* ── Footer ── */
.footer {
    margin-top: 20px;
    text-align: center;
    padding: 16px 0;
    animation: fadeInUp 0.6s cubic-bezier(0.16, 1, 0.3, 1) 0.55s both;
}

.footer p {
    font-size: 0.72rem;
    color: var(--text-faint);
    letter-spacing: 0.02em;
}

.footer-credit {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 10px;
    padding: 6px 14px;
    border-radius: 20px;
    border: 1px solid var(--border);
    background: rgba(255, 255, 255, 0.02);
    color: var(--text-faint);
    font-size: 0.72rem;
    text-decoration: none;
    transition: var(--transition);
    transition-property: color, border-color, background, transform;
}

.footer-credit:hover {
    color: var(--accent);
    border-color: var(--border-focus);
    background: var(--accent-soft);
    transform: translateY(-1px);
}

/* ── Scrollbar ── */
.text-area::-webkit-scrollbar,
.editor-display::-webkit-scrollbar {
    width: 6px;
}

.text-area::-webkit-scrollbar-track,
.editor-display::-webkit-scrollbar-track {
    background: transparent;
}

.text-area::-webkit-scrollbar-thumb,
.editor-display::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.08);
    border-radius: 3px;
}

.text-area::-webkit-scrollbar-thumb:hover,
.editor-display::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.14);
}

/* ── Responsive ── */
@media (max-width: 640px) {
    body {
        padding: 32px 14px 32px;
    }

    .title {
        font-size: 1.6rem;
    }

    .converter {
        flex-direction: column;
        gap: 0;
    }

    .divider {
        padding: 6px 0;
    }

    .arrow-icon {
        transform: rotate(90deg);
    }

    .method-track {
        flex-wrap: wrap;
    }

    .method-btn {
        flex: 0 0 calc(33.333% - 2px);
        padding: 9px 8px;
        font-size: 0.78rem;
    }

    .method-pill {
        display: none;
    }

    .method-btn.active {
        background: var(--accent-soft);
        border: 1px solid var(--border-focus);
    }

    .editor,
    .editor-display,
    .text-area {
        min-height: 140px;
    }

    /* Prevent iOS auto-zoom — inputs must be >= 16px */
    .editor-input,
    .editor-display {
        font-size: 16px;
    }

    /* Tap targets: minimum 44px */
    .btn-icon {
        min-width: 44px;
        min-height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .btn-copy {
        min-height: 44px;
    }

    .info-toggle {
        width: 36px;
        height: 36px;
    }

    /* Info bar compact */
    .info-bar {
        gap: 12px;
        padding: 10px;
    }

    .info-label {
        font-size: 0.7rem;
    }

    /* Detail card mobile */
    .detail-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }

    .detail-label {
        min-width: unset;
    }

    .coverage-bar {
        max-width: 100%;
    }

    /* Charmap items smaller on mobile */
    .charmap-item {
        padding: 4px 8px;
        font-size: 0.75rem;
    }

    .shortcut-hint {
        display: none !important;
    }

    .toast {
        left: 14px;
        right: 14px;
        transform: translateY(20px);
        text-align: center;
    }

    .toast.show {
        transform: translateY(0);
    }
}

/* ── Touch Devices ── */
@media (hover: none) and (pointer: coarse) {
    /* Use native caret on touch — custom caret fights with mobile keyboards */
    .editor-caret {
        display: none !important;
    }

    /* Hide the visual display on touch — native textarea shows text directly */
    .editor-display {
        display: none;
    }

    .editor-input {
        position: relative;
        height: auto;
        min-height: 140px;
        color: var(--text);
        caret-color: var(--accent);
        font-size: 16px;
    }

    .editor-input::placeholder {
        color: var(--text-faint);
    }
}

/* ── Focus Visible (keyboard navigation) ── */
:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Don't double-up outline on elements that already have custom focus */
.panel:focus-within :focus-visible,
.editor-input:focus-visible {
    outline: none;
}

/* ── Selection ── */
::selection {
    background: rgba(139, 92, 246, 0.3);
    color: #fff;
}

/* ── Reduced Motion ── */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    .glow {
        animation: none;
    }

    .editor-caret {
        transition: none;
    }

    .editor-caret.visible {
        animation: none;
        opacity: 1;
    }

    .editor-caret.solid {
        opacity: 1;
    }
}