:root {
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --secondary-color: #10b981;
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --card-border: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --input-bg: #0f172a;
    --success-color: #22c55e;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #fff;
    color: #181818;
    min-height: 100vh;
    line-height: 1.6;
    transition: background 0.3s, color 0.3s;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
    border-radius: 10px;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 20px;
    padding: 20px;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

header p {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Client-side note */
.client-side-note {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 10px;
    padding: 8px 16px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: 8px;
    display: inline-block;
}

.dark-mode .client-side-note {
    background: rgba(99, 102, 241, 0.15);
    color: #a5b4fc;
}

/* Topbar */
.topbar {
    display: flex;
    justify-content: flex-end;
    align-items: center;
    gap: 1.2rem;
    margin-top: 1.2rem;
    padding: 0 20px;
}

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

.theme-toggle-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.2em 0.2em;
    border-radius: 50%;
    background: none;
    border: none;
    cursor: pointer;
    transition: background 0.2s;
}

.theme-toggle-btn:focus {
    outline: none;
}

#theme-icon svg, .github-link svg {
    width: 28px !important;
    height: 28px !important;
    display: block;
    color: #181818;
    fill: #181818;
    transition: color 0.2s, fill 0.2s;
}

.dark-mode #theme-icon svg, .dark-mode .github-link svg {
    color: #fff !important;
    fill: #fff !important;
}

/* Main Content Layout */
.main-content {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

@media (min-width: 768px) {
    .main-content {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 20px;
    }
}

/* Sections */
.input-section,
.output-section {
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    padding: 20px;
    font-size: 0.95rem;
    transition: background 0.3s, color 0.3s, border-color 0.3s;
}

.input-section h2,
.output-section h2 {
    font-size: 1.2rem;
    margin-bottom: 15px;
    color: #181818;
    font-weight: 700;
    letter-spacing: 0.01em;
    transition: color 0.3s;
}

.dark-mode .input-section h2,
.dark-mode .output-section h2 {
    color: #e5e7eb;
}

/* Generator Type Selector */
.generator-type-selector {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
    gap: 10px;
    margin-bottom: 20px;
}

.generator-option {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    padding: 12px 16px;
    background: #f3f4f6;
    border: 2px solid #e5e7eb;
    border-radius: 10px;
    font-size: 0.9rem;
    color: #181818;
    font-weight: 500;
    transition: all 0.3s;
}

.generator-option:hover {
    border-color: var(--primary-color);
    background: #e0e7ff;
}

.generator-option input[type="radio"] {
    width: 16px;
    height: 16px;
    accent-color: var(--primary-color);
    cursor: pointer;
}

.generator-option input[type="radio"]:checked + span {
    color: var(--primary-color);
    font-weight: 700;
}

.dark-mode .generator-option {
    background: #23272b;
    border-color: #2d3237;
    color: #e5e7eb;
}

.dark-mode .generator-option:hover {
    background: #333a41;
    border-color: var(--primary-color);
}

.dark-mode .generator-option input[type="radio"]:checked + span {
    color: #a5b4fc;
}

/* Settings Section */
.settings-section {
    margin-bottom: 20px;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 15px;
    margin-bottom: 15px;
}

.setting-item {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.setting-item label {
    font-size: 0.9rem;
    font-weight: 600;
    color: #374151;
}

.dark-mode .setting-item label {
    color: #d1d5db;
}

.setting-item input[type="number"] {
    padding: 10px 12px;
    font-size: 1rem;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    background: #fff;
    color: #181818;
    transition: border-color 0.3s, background 0.3s;
}

.setting-item input[type="number"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

.dark-mode .setting-item input[type="number"] {
    background: #181c1f;
    border-color: #2d3237;
    color: #e5e7eb;
}

/* Custom Characters Section */
.custom-chars-section {
    margin-bottom: 15px;
}

.custom-chars-section label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: #374151;
    margin-bottom: 6px;
}

.dark-mode .custom-chars-section label {
    color: #d1d5db;
}

.custom-chars-section input[type="text"] {
    width: 100%;
    padding: 10px 12px;
    font-size: 1rem;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    background: #fff;
    color: #181818;
    transition: border-color 0.3s, background 0.3s;
}

.custom-chars-section input[type="text"]:focus {
    outline: none;
    border-color: var(--primary-color);
}

.dark-mode .custom-chars-section input[type="text"] {
    background: #181c1f;
    border-color: #2d3237;
    color: #e5e7eb;
}

/* Character Options */
.char-options {
    background: #f8fafc;
    border: 1px solid #e5e7eb;
    border-radius: 10px;
    padding: 15px;
    margin-bottom: 15px;
}

.char-options h3 {
    font-size: 0.95rem;
    margin-bottom: 12px;
    color: #374151;
    font-weight: 600;
}

.dark-mode .char-options {
    background: #181c1f;
    border-color: #2d3237;
}

.dark-mode .char-options h3 {
    color: #d1d5db;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 10px;
}

.option-item {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    padding: 10px 14px;
    background: #fff;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 0.85rem;
    color: #181818;
    font-weight: 500;
    transition: all 0.3s;
}

.option-item:hover {
    border-color: var(--primary-color);
    background: #e0e7ff;
}

.option-item input[type="checkbox"] {
    width: 16px;
    height: 16px;
    accent-color: var(--primary-color);
    cursor: pointer;
}

.dark-mode .option-item {
    background: #23272b;
    border-color: #2d3237;
    color: #e5e7eb;
}

.dark-mode .option-item:hover {
    background: #333a41;
    border-color: var(--primary-color);
}

/* Separator Section */
.separator-section {
    margin-bottom: 15px;
}

.separator-section label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: #374151;
    margin-bottom: 6px;
}

.dark-mode .separator-section label {
    color: #d1d5db;
}

.separator-section select {
    width: 100%;
    padding: 10px 12px;
    font-size: 0.95rem;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    background: #fff;
    color: #181818;
    cursor: pointer;
    transition: border-color 0.3s, background 0.3s;
}

.separator-section select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.dark-mode .separator-section select {
    background: #181c1f;
    border-color: #2d3237;
    color: #e5e7eb;
}

/* Generate Button */
.generate-btn {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 14px 30px;
    font-size: 1.1rem;
    font-weight: 600;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    border: none;
    border-radius: 10px;
    color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.3);
}

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

.generate-btn svg {
    fill: currentColor;
}

/* Text Areas */
textarea {
    width: 100%;
    min-height: 200px;
    padding: 15px;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 0.95rem;
    background: #fff;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    color: #181818;
    resize: vertical;
    transition: border-color 0.3s ease, background 0.3s;
}

textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

textarea::placeholder {
    color: #9ca3af;
}

.dark-mode textarea {
    background: #181c1f;
    border-color: #2d3237;
    color: #e5e7eb;
}

.dark-mode textarea::placeholder {
    color: #6b7280;
}

/* Stats Bar */
.stats-bar {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    padding: 12px;
    background: #f3f4f6;
    border-radius: 10px;
    margin: 15px 0;
    border: 1px solid rgba(99, 102, 241, 0.2);
}

.dark-mode .stats-bar {
    background: #181c1f;
    border-color: rgba(99, 102, 241, 0.3);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: #fff;
    border-radius: 6px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    border: 1px solid #e5e7eb;
}

.dark-mode .stat-item {
    background: #23272b;
    border-color: #2d3237;
}

.stat-label {
    font-size: 0.8rem;
    color: #64748b;
    font-weight: 500;
}

.dark-mode .stat-label {
    color: #94a3b8;
}

.stat-value {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--primary-color);
}

.dark-mode .stat-value {
    color: #a5b4fc;
}

/* Output Actions */
.output-actions {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}

.copy-btn,
.download-btn,
.regenerate-btn {
    padding: 10px 20px;
    font-size: 0.9rem;
    font-weight: 500;
    border: 2px solid #e5e7eb;
    background: #f3f4f6;
    color: #181818;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
}

.copy-btn:hover {
    border-color: var(--primary-color);
    background: #e0e7ff;
    color: var(--primary-color);
}

.download-btn:hover {
    border-color: var(--secondary-color);
    background: #d1fae5;
    color: var(--secondary-color);
}

.regenerate-btn:hover {
    border-color: #f59e0b;
    background: #fef3c7;
    color: #d97706;
}

.copy-btn.copied {
    background: var(--success-color);
    border-color: var(--success-color);
    color: white;
}

.dark-mode .copy-btn,
.dark-mode .download-btn,
.dark-mode .regenerate-btn {
    background: #23272b;
    border-color: #2d3237;
    color: #e5e7eb;
}

.dark-mode .copy-btn:hover {
    background: #333a41;
    border-color: var(--primary-color);
    color: #a5b4fc;
}

.dark-mode .download-btn:hover {
    background: #333a41;
    border-color: var(--secondary-color);
    color: #6ee7b7;
}

.dark-mode .regenerate-btn:hover {
    background: #333a41;
    border-color: #f59e0b;
    color: #fcd34d;
}

/* Status Messages */
.status {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    padding: 15px 30px;
    border-radius: 10px;
    font-weight: 500;
    z-index: 1000;
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateX(-50%) translateY(20px); }
    to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

.status.success {
    background: var(--success-color);
    color: white;
}

.status.error {
    background: var(--error-color);
    color: white;
}

.status.warning {
    background: var(--warning-color);
    color: white;
}

/* Hidden Class */
.hidden {
    display: none !important;
}

/* Visually Hidden */
.visually-hidden {
    position: absolute !important;
    height: 1px;
    width: 1px;
    overflow: hidden;
    clip: rect(1px, 1px, 1px, 1px);
    white-space: nowrap;
}

/* Footer */
footer {
    color: #181818;
    background: transparent;
    text-align: center;
    padding: 30px 0 10px 0;
    font-size: 0.95rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.3em;
}

footer a {
    color: var(--primary-color);
    text-decoration: underline;
    font-weight: 600;
    transition: color 0.2s;
}

footer .copyright {
    color: #374151;
    font-size: 0.9em;
    font-weight: 500;
    letter-spacing: 0.01em;
    margin-top: 0.5em;
}

.dark-mode footer {
    color: #e5e7eb;
}

.dark-mode footer a {
    color: #a5b4fc;
}

.dark-mode footer .copyright {
    color: #9ca3af;
}

/* Dark Mode */
.dark-mode {
    background: #181c1f;
    color: #e5e7eb;
}

.dark-mode .container {
    background: transparent;
}

.dark-mode .input-section,
.dark-mode .output-section {
    background: #23272b;
    border-color: #2d3237;
    color: #e5e7eb;
}

/* Responsive */
@media (max-width: 600px) {
    header h1 {
        font-size: 1.8rem;
    }

    .generator-type-selector {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

    .stats-bar {
        flex-direction: column;
    }

    .output-actions {
        grid-template-columns: 1fr;
    }

    .copy-btn,
    .download-btn,
    .regenerate-btn {
        width: 100%;
    }
}