/* ═══════════════════════════════════════════════
   Send2eReader — "Letterpress" Design System
   Editorial aesthetic inspired by bookshops
   and letterpress typography
   ═══════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=Libre+Baskerville:ital,wght@0,400;0,700;1,400&family=Source+Serif+4:ital,opsz,wght@0,8..60,400;0,8..60,600;1,8..60,400&family=JetBrains+Mono:wght@400;700&display=swap');

:root {
    --font-display: 'Libre Baskerville', Georgia, serif;
    --font-body: 'Source Serif 4', 'Palatino Linotype', Palatino, serif;
    --font-mono: 'JetBrains Mono', 'SF Mono', Consolas, monospace;

    --color-cream: #f6f1eb;
    --color-paper: #efe8df;
    --color-parchment: #e8dfd4;
    --color-ink: #2c2418;
    --color-ink-light: #5a4e3c;
    --color-amber: #c8873e;
    --color-amber-deep: #a86b28;
    --color-amber-glow: #e8a44e;
    --color-success: #4a7c59;
    --color-success-bg: #e8f2eb;
    --color-error: #9c3a3a;
    --color-error-bg: #f5e6e6;
    --color-rule: #d4c9b8;
    --color-shadow: rgba(44, 36, 24, 0.08);
    --color-surface: #fff;

    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2.5rem;
    --spacing-2xl: 4rem;
}

/* ── Reset & Base ─────────────────────────── */

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

html {
    font-size: 17px;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-body);
    color: var(--color-ink);
    background: var(--color-cream);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* Subtle paper grain texture */
body::before {
    content: '';
    position: fixed;
    top: 0; right: 0; bottom: 0; left: 0;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.025'/%3E%3C/svg%3E");
    pointer-events: none;
    z-index: -1;
}

a {
    color: var(--color-amber-deep);
    text-decoration-color: var(--color-parchment);
    text-underline-offset: 3px;
    transition: color 0.2s ease, text-decoration-color 0.2s ease;
}
a:hover {
    color: var(--color-amber);
    text-decoration-color: var(--color-amber);
}

/* ── Layout ───────────────────────────────── */

.wrapper {
    width: 100%;
    max-width: 640px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-lg);
}

/* ── Toolbar ──────────────────────────────── */

.toolbar {
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.toolbar__btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--color-paper);
    border: 1px solid var(--color-rule);
    border-radius: 50%;
    cursor: pointer;
    color: var(--color-ink-light);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0;
    transition: all 0.2s ease;
}

.toolbar__btn:hover {
    background: var(--color-amber);
    border-color: var(--color-amber);
    color: #fff;
}

.toolbar__btn svg {
    width: 18px;
    height: 18px;
}

/* ── Header ───────────────────────────────── */

.site-header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.site-header__icon {
    display: inline-block;
    width: 48px;
    height: 48px;
    margin-bottom: var(--spacing-md);
    color: var(--color-amber);
    animation: fadeDown 0.6s ease both;
}

.site-header__title {
    font-family: var(--font-display);
    font-weight: 400;
    font-style: italic;
    font-size: 2rem;
    color: var(--color-ink);
    letter-spacing: -0.02em;
    animation: fadeDown 0.6s ease 0.1s both;
}

.site-header__subtitle {
    font-family: var(--font-body);
    font-size: 0.95rem;
    color: var(--color-ink-light);
    margin-top: var(--spacing-xs);
    font-style: italic;
    animation: fadeDown 0.6s ease 0.2s both;
}

/* ── Card ─────────────────────────────────── */

.card {
    background: var(--color-surface);
    border: 1px solid var(--color-rule);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    min-height: 320px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    box-shadow:
        0 1px 3px var(--color-shadow),
        0 8px 24px var(--color-shadow);
    animation: fadeUp 0.5s ease 0.3s both;
}

.card--form {
    min-height: 0;
    justify-content: flex-start;
}

.card + .card {
    margin-top: var(--spacing-lg);
}

.card__label {
    font-family: var(--font-display);
    font-size: 0.8rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-ink-light);
    margin-bottom: var(--spacing-sm);
}

/* ── Key Display (Download Page) ──────────── */

.key-display {
    text-align: center;
    padding: var(--spacing-lg) 0;
}

.key-display__label {
    font-family: var(--font-display);
    font-size: 0.85rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-ink-light);
    margin-bottom: var(--spacing-sm);
}

.key-display__value {
    font-family: var(--font-mono);
    font-size: 3.5rem;
    font-size: clamp(3rem, 12vw, 5rem);
    font-weight: 700;
    letter-spacing: 0.25em;
    color: var(--color-ink);
    text-transform: uppercase;
    line-height: 1;
    display: inline-block;
    vertical-align: middle;
}

.key-display__refresh {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: var(--color-paper);
    border: 1px solid var(--color-rule);
    border-radius: 50%;
    cursor: pointer;
    vertical-align: middle;
    margin-top: var(--spacing-sm);
    color: var(--color-ink-light);
    transition: all 0.2s ease;
}

.key-display__refresh:hover {
    background: var(--color-amber);
    border-color: var(--color-amber);
    color: #fff;
    transform: rotate(60deg);
}
.key-display__refresh:active {
    transform: rotate(180deg) scale(0.95);
}

.key-display__refresh svg {
    width: 20px;
    height: 20px;
}

/* ── Download Section ─────────────────────── */

.download-section {
    display: none;
    text-align: center;
    margin-top: var(--spacing-lg);
}

.download-section__label {
    font-family: var(--font-display);
    font-size: 0.85rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-ink-light);
    margin-bottom: var(--spacing-md);
}

.download-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--color-amber);
    color: #fff;
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 400;
    padding: 0.75em 1.5em;
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: all 0.2s ease;
    box-shadow: 0 2px 8px rgba(200, 135, 62, 0.3);
}

.download-btn:hover {
    background: var(--color-amber-deep);
    color: #fff;
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(200, 135, 62, 0.4);
}

.download-btn svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

/* ── URLs Section ─────────────────────────── */

.urls-section {
    text-align: center;
    margin-top: var(--spacing-lg);
}

.urls-section__label {
    font-family: var(--font-display);
    font-size: 0.85rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-ink-light);
    margin-bottom: var(--spacing-sm);
}

.url-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    margin: var(--spacing-xs) 0;
    background: var(--color-paper);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    word-break: break-all;
}

/* ── Form Elements ────────────────────────── */

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group__label {
    display: block;
    font-family: var(--font-display);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--color-ink);
    margin-bottom: var(--spacing-sm);
}

.form-group__hint {
    font-size: 0.8rem;
    color: var(--color-ink-light);
    font-style: italic;
    margin-top: var(--spacing-xs);
}

.form-group__hint-inline {
    font-weight: 400;
    font-style: italic;
    font-size: 0.85em;
    color: var(--color-ink-light);
}

.form-input {
    width: 100%;
    padding: 0.7em 0.9em;
    font-family: var(--font-body);
    font-size: 1rem;
    color: var(--color-ink);
    background: var(--color-surface);
    border: 1px solid var(--color-rule);
    border-radius: var(--radius-md);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--color-amber);
    box-shadow: 0 0 0 3px rgba(200, 135, 62, 0.15);
}

.form-input--key {
    font-family: var(--font-mono);
    font-size: 2.4rem;
    font-weight: 700;
    text-align: center;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    padding: 0.4em 0.6em;
    max-width: 240px;
    margin: 0 auto;
    display: block;
}

/* ── File Picker ──────────────────────────── */

.file-picker {
    position: relative;
}

.file-picker__dropzone {
    border: 2px dashed var(--color-rule);
    border-radius: var(--radius-md);
    padding: var(--spacing-xl) var(--spacing-lg);
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    background: var(--color-cream);
}

.file-picker__dropzone:hover,
.file-picker__dropzone.dragover {
    border-color: var(--color-amber);
    background: rgba(200, 135, 62, 0.05);
}

.file-picker__icon {
    width: 40px;
    height: 40px;
    margin: 0 auto var(--spacing-sm);
    color: var(--color-ink-light);
}

.file-picker__text {
    font-size: 0.95rem;
    color: var(--color-ink-light);
}

.file-picker__text strong {
    color: var(--color-amber);
    cursor: pointer;
}

.file-picker__formats {
    font-size: 0.75rem;
    color: var(--color-ink-light);
    margin-top: var(--spacing-sm);
    font-style: italic;
}

.file-picker__info {
    margin-top: var(--spacing-sm);
    font-size: 0.85rem;
    color: var(--color-ink);
    font-style: italic;
    min-height: 1.4em;
}

/* ── File Picker: File Selected State ────── */

.file-picker__dropzone.has-file {
    border-style: solid;
    border-color: var(--color-amber);
    background: rgba(200, 135, 62, 0.06);
    padding: var(--spacing-lg);
}

.file-picker__dropzone.has-file .file-picker__icon,
.file-picker__dropzone.has-file .file-picker__text,
.file-picker__dropzone.has-file .file-picker__formats {
    display: none;
}

.file-picker__selected {
    display: none;
    align-items: center;
    gap: var(--spacing-md);
}

.file-picker__dropzone.has-file .file-picker__selected {
    display: flex;
}

.file-picker__selected-icon {
    width: 36px;
    height: 36px;
    flex-shrink: 0;
    color: var(--color-amber);
}

.file-picker__selected-details {
    flex: 1;
    text-align: left;
    min-width: 0;
}

.file-picker__selected-name {
    font-family: var(--font-display);
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--color-ink);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-picker__selected-size {
    font-size: 0.8rem;
    color: var(--color-ink-light);
    font-style: italic;
    margin-top: 0.1em;
}

.file-picker__change-btn {
    flex-shrink: 0;
    font-family: var(--font-display);
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--color-amber);
    background: transparent;
    border: 1.5px solid var(--color-amber);
    border-radius: var(--radius-sm);
    padding: 0.35em 0.7em;
    cursor: pointer;
    transition: all 0.15s ease;
    pointer-events: none;
}

.file-picker__dropzone.has-file:hover .file-picker__change-btn {
    background: var(--color-amber);
    color: #fff;
}

.file-picker input[type="file"] {
    position: absolute;
    top: 0; right: 0; bottom: 0; left: 0;
    opacity: 0;
    cursor: pointer;
}

/* ── Checkboxes ───────────────────────────── */

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
}

.option {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background 0.15s ease;
}

.option:hover {
    background: var(--color-cream);
}

.option input[type="checkbox"] {
    appearance: none;
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border: 2px solid var(--color-rule);
    border-radius: 3px;
    margin-top: 2px;
    flex-shrink: 0;
    cursor: pointer;
    transition: all 0.15s ease;
    position: relative;
}

.option input[type="checkbox"]:checked {
    background: var(--color-amber);
    border-color: var(--color-amber);
}

.option input[type="checkbox"]:checked::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 5px;
    width: 5px;
    height: 9px;
    border: 2px solid #fff;
    border-top: none;
    border-left: none;
    transform: rotate(45deg);
}

.option__text {
    font-size: 0.9rem;
    line-height: 1.4;
}

.option__text strong {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 0.85rem;
}

.option__text small {
    display: block;
    font-size: 0.75rem;
    color: var(--color-ink-light);
    margin-top: 0.15em;
}

.option__badge {
    display: inline-block;
    font-size: 0.65rem;
    font-family: var(--font-mono);
    letter-spacing: 0.05em;
    text-transform: uppercase;
    background: var(--color-paper);
    color: var(--color-ink-light);
    padding: 1px 6px;
    border-radius: 3px;
    margin-left: 4px;
    vertical-align: middle;
}

/* ── Submit Button ────────────────────────── */

.btn-submit {
    display: block;
    width: 100%;
    padding: 0.85em;
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 700;
    color: #fff;
    background: var(--color-ink);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
    overflow: hidden;
}

.btn-submit:hover {
    background: var(--color-amber-deep);
    transform: translateY(-1px);
    box-shadow: 0 4px 16px var(--color-shadow);
}

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

/* ── Progress Bar ─────────────────────────── */

.progress-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 3px;
    background: var(--color-amber-glow);
    transition: width 0.3s ease;
    border-radius: 0 0 var(--radius-md) var(--radius-md);
}

/* ── Status Toast ─────────────────────────── */

.status-toast {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    text-align: center;
    font-size: 0.9rem;
    cursor: pointer;
    opacity: 0;
    transform: translateY(-8px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.status-toast.visible {
    opacity: 1;
    transform: translateY(0);
}

.status-toast.success {
    background: var(--color-success-bg);
    border: 1px solid var(--color-success);
    color: var(--color-success);
}

.status-toast.error {
    background: var(--color-error-bg);
    border: 1px solid var(--color-error);
    color: var(--color-error);
}

/* ── Upload Success State ────────────────── */

.upload-done {
    text-align: center;
    padding: var(--spacing-xl) 0;
    animation: fadeUp 0.4s ease;
}

.upload-done__icon {
    display: block;
    width: 56px;
    height: 56px;
    margin: 0 auto var(--spacing-md);
    color: var(--color-success);
}

.upload-done__title {
    font-family: var(--font-display);
    font-size: 1.4rem;
    font-weight: 400;
    font-style: italic;
    color: var(--color-ink);
    margin-bottom: var(--spacing-sm);
}

.upload-done__file {
    font-size: 0.9rem;
    color: var(--color-ink-light);
    font-style: italic;
    margin-bottom: var(--spacing-xl);
}

.btn-reset {
    display: inline-block;
    padding: 0.7em 1.5em;
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-amber);
    background: transparent;
    border: 2px solid var(--color-amber);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-reset:hover {
    background: var(--color-amber);
    color: #fff;
}

/* ── Divider ──────────────────────────────── */

.divider {
    border: none;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--color-rule), transparent);
    margin: var(--spacing-xl) 0;
}

/* ── Footer ───────────────────────────────── */

.site-footer {
    text-align: center;
    font-size: 0.8rem;
    color: var(--color-ink-light);
    line-height: 1.8;
    padding-bottom: var(--spacing-xl);
    animation: fadeUp 0.5s ease 0.5s both;
}

/* ── Info Section ─────────────────────────── */

.info-section {
    margin-top: var(--spacing-lg);
    animation: fadeUp 0.5s ease 0.4s both;
}

.info-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    background: none;
    border: none;
    font-family: var(--font-display);
    font-size: 0.85rem;
    color: var(--color-ink-light);
    cursor: pointer;
    padding: var(--spacing-sm) var(--spacing-md);
    margin: 0 auto;
    transition: color 0.2s ease;
}

.info-toggle:hover {
    color: var(--color-amber);
}

.info-toggle svg {
    width: 16px;
    height: 16px;
    transition: transform 0.2s ease;
}

.info-toggle[aria-expanded="true"] svg {
    transform: rotate(180deg);
}

.info-content {
    display: none;
    padding: var(--spacing-lg);
    font-size: 0.85rem;
    color: var(--color-ink-light);
    line-height: 1.7;
    text-align: left;
}

.info-content.open {
    display: block;
    animation: fadeUp 0.3s ease;
}

.info-content p + p {
    margin-top: var(--spacing-md);
}

/* ── Waiting state (Download Page) ────────── */

.waiting-message {
    text-align: center;
    padding: var(--spacing-lg) 0;
    color: var(--color-ink-light);
    font-style: italic;
    font-size: 0.95rem;
}

.waiting-dots::after {
    content: '';
    animation: dots 1.5s steps(4, end) infinite;
}

@keyframes dots {
    0%, 20% { content: ''; }
    40% { content: '.'; }
    60% { content: '..'; }
    80%, 100% { content: '...'; }
}

/* ── Animations (progressive enhancement) ─── */

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeDown {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ── Dark Theme ───────────────────────────── */

[data-theme="dark"] {
    --color-cream: #181410;
    --color-paper: #221e18;
    --color-parchment: #2a241c;
    --color-ink: #ddd0be;
    --color-ink-light: #9a8a74;
    --color-amber: #d49530;
    --color-amber-deep: #b87e20;
    --color-amber-glow: #e8a840;
    --color-success: #5a9a68;
    --color-success-bg: #1a261e;
    --color-error: #c04848;
    --color-error-bg: #2a1818;
    --color-rule: #362e24;
    --color-shadow: rgba(0, 0, 0, 0.35);
    --color-surface: #201c16;
}

[data-theme="dark"] a {
    text-decoration-color: var(--color-rule);
}

[data-theme="dark"] .btn-submit {
    background: var(--color-amber);
}

[data-theme="dark"] .btn-submit:hover {
    background: var(--color-amber-deep);
}

[data-theme="dark"] .file-picker__dropzone:hover,
[data-theme="dark"] .file-picker__dropzone.dragover {
    background: rgba(212, 149, 48, 0.08);
}

[data-theme="dark"] .form-input:focus {
    box-shadow: 0 0 0 3px rgba(212, 149, 48, 0.2);
}

[data-theme="dark"] .option input[type="checkbox"] {
    border-color: var(--color-ink-light);
}

/* ── Responsive ───────────────────────────── */

@media (max-width: 480px) {
    html { font-size: 15px; }

    .wrapper { padding: var(--spacing-lg) var(--spacing-md); }

    .card { min-height: 260px; }

    .card { padding: var(--spacing-lg); }

    .options-grid { grid-template-columns: 1fr; }

    .key-display__value { font-size: 3rem; }

    .form-input--key { font-size: 2rem; max-width: 200px; }
}

/* ── Accessibility ────────────────────────── */

:focus-visible {
    outline: 2px solid var(--color-amber);
    outline-offset: 2px;
}

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

/* ── E-ink Display Optimizations ──────────── */

@media (prefers-contrast: more) {
    :root, [data-theme] {
        --color-cream: #fff;
        --color-paper: #eee;
        --color-ink: #000;
        --color-ink-light: #333;
        --color-amber: #000;
        --color-amber-deep: #000;
        --color-rule: #999;
        --color-surface: #fff;
    }
    body::before { display: none; }
}

@media (update: slow) {
    *, *::before, *::after {
        transition: none !important;
        animation: none !important;
    }
    body::before { display: none; }

    /* E Ink Kaleido 3 color optimizations:
       - Higher saturation to compensate for washed-out colors
       - Stronger contrast for better readability at 150 PPI color
       - Simplified backgrounds (no gradients/textures) */
    :root, [data-theme] {
        --color-cream: #f5efe6;
        --color-paper: #ece3d5;
        --color-amber: #d4841a;
        --color-amber-deep: #b86d10;
        --color-amber-glow: #e89530;
        --color-success: #2d7a3a;
        --color-success-bg: #d6f0dc;
        --color-error: #b82020;
        --color-error-bg: #f5d4d4;
        --color-ink: #1a1208;
        --color-ink-light: #3d3020;
        --color-surface: #fff;
    }

    .download-btn {
        font-weight: 700;
        letter-spacing: 0.02em;
    }

    .divider {
        background: var(--color-rule);
    }
}

/* ── Debug logs (hidden) ──────────────────── */

#logs {
    display: none;
}