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

:root {
    --bg: #0f172a;
    --surface: #1e293b;
    --surface-hover: #263548;
    --accent: #60a5fa;
    --accent-bold: #3b82f6;
    --accent-glow: rgba(59, 130, 246, 0.25);
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-dim: #64748b;
    --border: rgba(255, 255, 255, 0.08);
    --border-light: rgba(255, 255, 255, 0.12);
    --radius: 10px;
    --radius-lg: 14px;
    --radius-sm: 6px;
    --gradient-header: linear-gradient(135deg, #1e3a5f 0%, #2563eb 50%, #7c3aed 100%);
    --red: #ef4444;
    --orange: #f97316;
    --yellow: #eab308;
    --green: #22c55e;
    --emerald: #10b981;
    --char-letter: #60a5fa;
    --char-number: #f59e0b;
    --char-symbol: #f472b6;
    --transition: 0.2s ease;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.5;
}

/* ===== Top Bar ===== */
.top-bar {
    background: var(--gradient-header);
    padding: 1.25rem 1.5rem;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
}

.top-bar-inner {
    max-width: 640px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-icon {
    width: 28px;
    height: 28px;
    color: #fff;
    flex-shrink: 0;
}

.top-bar h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: #fff;
    letter-spacing: -0.01em;
}

/* ===== Container ===== */
.container {
    max-width: 640px;
    margin: 0 auto;
    padding: 1.5rem 1rem 3rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

/* ===== Card ===== */
.card {
    background: var(--surface);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    overflow: hidden;
}

/* ===== Password Display ===== */
.password-display-card {
    padding: 1.5rem;
}

.password-output-wrap {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
}

.password-output {
    flex: 1;
    font-family: 'SF Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
    font-size: 1.35rem;
    font-weight: 500;
    line-height: 1.6;
    word-break: break-all;
    min-height: 2.5rem;
    padding: 0.5rem 0;
    user-select: all;
    cursor: text;
}

.password-output .char-letter {
    color: var(--char-letter);
}

.password-output .char-number {
    color: var(--char-number);
}

.password-output .char-symbol {
    color: var(--char-symbol);
}

.password-output .char-separator {
    color: var(--text-dim);
}

.password-actions {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    flex-shrink: 0;
    padding-top: 0.4rem;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    border: none;
    cursor: pointer;
    font-family: inherit;
    font-weight: 500;
    transition: all var(--transition);
    white-space: nowrap;
}

.btn-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius);
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    position: relative;
}

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

.btn-icon:active {
    transform: scale(0.93);
}

.btn-icon .icon {
    width: 18px;
    height: 18px;
}

.btn-icon .copy-feedback {
    position: absolute;
    top: 50%;
    right: calc(100% + 8px);
    transform: translateY(-50%);
    background: var(--accent-bold);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 600;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
    white-space: nowrap;
}

.btn-icon .copy-feedback.show {
    opacity: 1;
}

.btn-sm {
    font-size: 0.8rem;
    padding: 0.4rem 0.85rem;
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--border);
    color: var(--text-secondary);
}

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

.btn-sm:active {
    transform: scale(0.95);
}

.btn-accent {
    background: var(--accent-bold);
    border-color: var(--accent-bold);
    color: #fff;
}

.btn-accent:hover {
    background: #4b93f7;
    color: #fff;
}

.btn-subtle {
    background: transparent;
    border-color: transparent;
    color: var(--text-dim);
}

.btn-subtle:hover {
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.04);
}

.icon-xs {
    width: 14px;
    height: 14px;
}

.icon-sm {
    width: 16px;
    height: 16px;
}

/* ===== Strength Meter ===== */
.strength-section {
    margin-top: 1.25rem;
}

.strength-bar-track {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.06);
    overflow: hidden;
}

.strength-bar-fill {
    height: 100%;
    border-radius: 3px;
    width: 0%;
    transition: width 0.4s ease, background-color 0.4s ease;
}

.strength-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 0.5rem;
}

.strength-label {
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.entropy-display {
    font-size: 0.75rem;
    color: var(--text-dim);
    font-variant-numeric: tabular-nums;
}

.strength-quip {
    margin-top: 0.5rem;
    font-size: 0.8rem;
    color: var(--text-dim);
    font-style: italic;
    min-height: 1.2em;
    transition: opacity 0.25s;
}

/* Strength colors */
.strength-weak .strength-bar-fill { background: var(--red); }
.strength-weak .strength-label { color: var(--red); }

.strength-fair .strength-bar-fill { background: var(--orange); }
.strength-fair .strength-label { color: var(--orange); }

.strength-good .strength-bar-fill { background: var(--yellow); }
.strength-good .strength-label { color: var(--yellow); }

.strength-strong .strength-bar-fill { background: var(--green); }
.strength-strong .strength-label { color: var(--green); }

.strength-very-strong .strength-bar-fill { background: var(--emerald); }
.strength-very-strong .strength-label { color: var(--emerald); }

/* ===== Mode Tabs ===== */
.mode-tabs {
    display: flex;
    border-bottom: 1px solid var(--border);
}

.mode-tab {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.85rem 1rem;
    background: transparent;
    border: none;
    color: var(--text-dim);
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
    position: relative;
}

.mode-tab::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
    height: 2px;
    background: transparent;
    transition: background var(--transition);
}

.mode-tab:hover {
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.02);
}

.mode-tab.active {
    color: var(--accent);
}

.mode-tab.active::after {
    background: var(--accent);
}

/* ===== Settings Panel ===== */
.settings-panel {
    padding: 1.25rem 1.5rem 1.5rem;
}

.setting-group {
    margin-bottom: 1.25rem;
}

.setting-group:last-child {
    margin-bottom: 0;
}

.setting-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.6rem;
}

.setting-header label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
}

.setting-value {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
    min-width: 2.5rem;
    text-align: right;
}

.group-label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 0.6rem;
}

/* ===== Slider ===== */
.slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.08);
    outline: none;
    cursor: pointer;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 2px solid var(--surface);
    box-shadow: 0 0 0 3px var(--accent-glow);
    transition: transform 0.15s ease;
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.15);
}

.slider::-webkit-slider-thumb:active {
    transform: scale(1.05);
}

.slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 2px solid var(--surface);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.slider-labels {
    display: flex;
    justify-content: space-between;
    margin-top: 0.35rem;
    font-size: 0.7rem;
    color: var(--text-dim);
}

/* ===== Checkbox ===== */
.checkbox-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.5rem;
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    padding: 0.5rem 0.65rem;
    border-radius: var(--radius-sm);
    transition: background var(--transition);
}

.checkbox-item:hover {
    background: rgba(255, 255, 255, 0.03);
}

.checkbox-item input[type="checkbox"] {
    display: none;
}

.checkmark {
    width: 18px;
    height: 18px;
    border-radius: 4px;
    border: 2px solid var(--text-dim);
    flex-shrink: 0;
    position: relative;
    transition: all var(--transition);
}

.checkbox-item input[type="checkbox"]:checked + .checkmark {
    background: var(--accent-bold);
    border-color: var(--accent-bold);
}

.checkbox-item input[type="checkbox"]:checked + .checkmark::after {
    content: '';
    position: absolute;
    left: 4px;
    top: 1px;
    width: 6px;
    height: 10px;
    border: solid #fff;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.checkbox-label {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.3;
}

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

/* ===== Exclude Custom ===== */
.exclude-custom {
    margin-top: 0.75rem;
}

.exclude-custom label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-dim);
    margin-bottom: 0.35rem;
}

.text-input {
    width: 100%;
    padding: 0.5rem 0.75rem;
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.85rem;
    outline: none;
    transition: border-color var(--transition);
}

.text-input:focus {
    border-color: var(--accent);
}

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

/* ===== Separator Options ===== */
.separator-options {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    align-items: center;
}

.sep-btn {
    padding: 0.4rem 0.85rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-family: 'SF Mono', 'Consolas', monospace;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition);
}

.sep-btn:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--border-light);
}

.sep-btn.active {
    background: var(--accent-glow);
    border-color: var(--accent);
    color: var(--accent);
}

.custom-sep-wrap {
    flex: 0 0 auto;
}

.sep-input {
    width: 80px;
    padding: 0.4rem 0.6rem;
    font-size: 0.85rem;
    text-align: center;
}

/* ===== Bulk Generate ===== */
.bulk-card {
    padding: 1.25rem 1.5rem;
}

.bulk-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
}

.section-title {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
}

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

.bulk-count-btns {
    display: flex;
    gap: 0.35rem;
}

.bulk-list {
    max-height: 320px;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--text-dim) transparent;
}

.bulk-list::-webkit-scrollbar {
    width: 5px;
}

.bulk-list::-webkit-scrollbar-thumb {
    background: var(--text-dim);
    border-radius: 3px;
}

.bulk-placeholder,
.history-placeholder {
    font-size: 0.82rem;
    color: var(--text-dim);
    text-align: center;
    padding: 1.25rem 0;
}

.bulk-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.45rem 0;
    border-bottom: 1px solid var(--border);
    gap: 0.5rem;
}

.bulk-item:last-child {
    border-bottom: none;
}

.bulk-item-index {
    font-size: 0.7rem;
    color: var(--text-dim);
    min-width: 1.5rem;
    font-variant-numeric: tabular-nums;
}

.bulk-item-password {
    flex: 1;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.78rem;
    color: var(--text-secondary);
    word-break: break-all;
    line-height: 1.4;
    cursor: text;
    user-select: all;
}

.bulk-item-copy {
    padding: 0.2rem 0.5rem;
    font-size: 0.7rem;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-dim);
    cursor: pointer;
    transition: all var(--transition);
    flex-shrink: 0;
}

.bulk-item-copy:hover {
    border-color: var(--accent);
    color: var(--accent);
}

/* ===== History ===== */
.history-card {
    overflow: hidden;
}

.history-toggle {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    padding: 1rem 1.5rem;
    background: transparent;
    border: none;
    cursor: pointer;
    color: inherit;
    font-family: inherit;
}

.history-toggle:hover {
    background: rgba(255, 255, 255, 0.02);
}

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

.history-count {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-dim);
    background: rgba(255, 255, 255, 0.06);
    padding: 0.15rem 0.5rem;
    border-radius: 10px;
    font-variant-numeric: tabular-nums;
}

.chevron {
    color: var(--text-dim);
    transition: transform 0.3s ease;
}

.history-panel {
    overflow: hidden;
    transition: max-height 0.35s ease, opacity 0.25s ease;
    max-height: 600px;
    opacity: 1;
}

.history-panel.collapsed {
    max-height: 0;
    opacity: 0;
}

.history-toggle .chevron {
    transform: rotate(0deg);
}

.history-panel.collapsed ~ .history-toggle .chevron,
.history-card:has(.history-panel.collapsed) .chevron {
    transform: rotate(-90deg);
}

.history-list {
    padding: 0 1.5rem;
    max-height: 300px;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--text-dim) transparent;
}

.history-list::-webkit-scrollbar {
    width: 5px;
}

.history-list::-webkit-scrollbar-thumb {
    background: var(--text-dim);
    border-radius: 3px;
}

.history-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 0;
    border-bottom: 1px solid var(--border);
}

.history-item:last-child {
    border-bottom: none;
}

.history-item-time {
    font-size: 0.68rem;
    color: var(--text-dim);
    min-width: 3.2rem;
    flex-shrink: 0;
}

.history-item-password {
    flex: 1;
    font-family: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    font-size: 0.78rem;
    color: var(--text-secondary);
    word-break: break-all;
    line-height: 1.4;
    cursor: text;
    user-select: all;
}

.history-item-copy {
    padding: 0.2rem 0.5rem;
    font-size: 0.7rem;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-dim);
    cursor: pointer;
    transition: all var(--transition);
    flex-shrink: 0;
}

.history-item-copy:hover {
    border-color: var(--accent);
    color: var(--accent);
}

#btnClearHistory {
    margin: 0.75rem 1.5rem 1rem;
}

/* ===== Responsive ===== */
@media (max-width: 520px) {
    .container {
        padding: 1rem 0.6rem 2rem;
    }

    .password-output {
        font-size: 1.05rem;
    }

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

    .settings-panel {
        padding: 1rem 1.1rem 1.25rem;
    }

    .bulk-card {
        padding: 1rem 1.1rem;
    }

    .history-list {
        padding: 0 1.1rem;
    }

    #btnClearHistory {
        margin-left: 1.1rem;
        margin-right: 1.1rem;
    }

    .bulk-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
}