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

:root {
    --bg-body: #0E1117;
    --bg-card: #1A1F29;
    --border-color: #2B3445;
    --accent: #4F8CFF;
    --accent-hover: #6BA0FF;
    --accent-glow: rgba(79, 140, 255, 0.25);
    --text-primary: #EAECF0;
    --text-secondary: #9BA3B5;
    --text-muted: #6B7280;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --shadow-card: 0 10px 40px rgba(0, 0, 0, 0.35);
    --shadow-card-hover: 0 16px 56px rgba(0, 0, 0, 0.5);
    --transition-fast: 0.15s ease;
    --transition-smooth: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --font-heading: 'Electrolize', sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --max-width-content: 1100px;
    --max-width-text: 780px;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* ===== Header ===== */
.header {
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-color);
    background: rgba(14, 17, 23, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header__inner {
    max-width: var(--max-width-content);
    margin: 0 auto;
    display: flex;
    align-items: center;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text-primary);
    transition: opacity var(--transition-fast);
}

.logo:hover {
    opacity: 0.85;
}

.logo__icon {
    flex-shrink: 0;
}

.logo__text {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 400;
    letter-spacing: 0.02em;
}

/* ===== Hero ===== */
.hero {
    text-align: center;
    padding: 48px 24px 36px;
    max-width: var(--max-width-text);
    margin: 0 auto;
}

.hero__title {
    font-family: var(--font-heading);
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 400;
    color: var(--text-primary);
    margin-bottom: 12px;
    letter-spacing: 0.01em;
}

.hero__subtitle {
    font-family: var(--font-body);
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.5;
    max-width: 600px;
    margin: 0 auto;
}

/* ===== Tool Section ===== */
.tool {
    max-width: var(--max-width-content);
    margin: 0 auto;
    padding: 0 24px 32px;
}

.tool__container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 20px;
}

/* ===== Cards ===== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 20px 20px 16px;
    box-shadow: var(--shadow-card);
    transition: transform var(--transition-smooth), box-shadow var(--transition-smooth), border-color var(--transition-smooth);
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-card-hover);
    border-color: #3B4559;
}

.card--output {
    position: relative;
}

.card--output::before {
    content: '';
    position: absolute;
    inset: -1px;
    border-radius: var(--radius-lg);
    padding: 1px;
    background: linear-gradient(135deg, transparent 40%, var(--accent-glow) 70%, transparent 100%);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask-composite: xor;
    mask-composite: exclude;
    pointer-events: none;
    opacity: 0.6;
}

.card__header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
}

.card__title {
    font-family: var(--font-heading);
    font-size: 0.95rem;
    font-weight: 400;
    color: var(--text-primary);
    letter-spacing: 0.02em;
}

/* ===== Textarea ===== */
.card__textarea {
    flex: 1;
    min-height: 260px;
    width: 100%;
    max-width: 100%;
    padding: 14px 16px;
    font-family: var(--font-body);
    font-size: 0.95rem;
    line-height: 1.55;
    color: var(--text-primary);
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    resize: vertical;
    outline: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    -webkit-user-select: text;
    -moz-user-select: text;
    -ms-user-select: text;
    user-select: text;
}

.card__textarea::placeholder {
    color: var(--text-muted);
    opacity: 0.7;
}

.card__textarea:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.card__textarea--dragover {
    border-color: var(--accent) !important;
    box-shadow: 0 0 0 4px var(--accent-glow) !important;
    background: rgba(79, 140, 255, 0.04) !important;
}

.card__textarea[readonly] {
    cursor: default;
    background: rgba(0, 0, 0, 0.15);
}

/* ===== Card Stats ===== */
.card__stats {
    display: flex;
    flex-wrap: wrap;
    gap: 12px 18px;
    margin-top: 12px;
    padding-top: 10px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.stat {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 0.78rem;
    font-family: var(--font-body);
}

.stat__label {
    color: var(--text-muted);
}

.stat__value {
    color: var(--text-secondary);
    font-weight: 500;
    font-variant-numeric: tabular-nums;
}

/* ===== Action Buttons ===== */
.tool__actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin-bottom: 16px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 10px 18px;
    font-family: var(--font-body);
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: var(--radius-sm);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-smooth);
    white-space: nowrap;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

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

.btn--secondary {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--border-color);
    color: var(--text-secondary);
}

.btn--secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: #4B5563;
    color: var(--text-primary);
}

.btn--accent {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    box-shadow: 0 2px 12px rgba(79, 140, 255, 0.3);
}

.btn--accent:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    box-shadow: 0 4px 20px rgba(79, 140, 255, 0.45);
}

.btn--copied {
    background: #22C55E !important;
    border-color: #22C55E !important;
    box-shadow: 0 2px 12px rgba(34, 197, 94, 0.35) !important;
}

/* ===== Tool Hint ===== */
.tool__hint {
    text-align: center;
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.tool__hint code {
    background: rgba(255, 255, 255, 0.06);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.8rem;
}

/* ===== Info / SEO Sections ===== */
.info {
    padding: 32px 24px 48px;
    border-top: 1px solid var(--border-color);
    margin-top: 16px;
}

.info__container {
    max-width: var(--max-width-text);
    margin: 0 auto;
}

.info__block {
    margin-bottom: 40px;
}

.info__block h2 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--text-primary);
    margin-bottom: 14px;
    letter-spacing: 0.01em;
}

.info__block h3 {
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.info__block p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.65;
    margin-bottom: 12px;
}

.info__list {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.info__list li {
    font-size: 0.95rem;
    color: var(--text-secondary);
    padding-left: 22px;
    position: relative;
    line-height: 1.55;
}

.info__list li::before {
    content: '•';
    position: absolute;
    left: 4px;
    color: var(--accent);
    font-weight: 700;
}

.info__list--check li::before {
    content: '✓';
    color: #22C55E;
    font-weight: 700;
}

.info__list code,
.info__block p code {
    background: rgba(255, 255, 255, 0.06);
    padding: 1px 6px;
    border-radius: 4px;
    font-size: 0.85rem;
    color: var(--accent);
}

/* ===== Info Grid (When to Use) ===== */
.info__grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 16px;
    margin-top: 16px;
}

.info__card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 18px;
    transition: border-color var(--transition-smooth), transform var(--transition-smooth);
}

.info__card:hover {
    border-color: #3B4559;
    transform: translateY(-2px);
}

.info__card-icon {
    font-size: 1.5rem;
    display: block;
    margin-bottom: 8px;
}

.info__card h3 {
    margin-bottom: 4px;
}

.info__card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin: 0;
}

/* ===== Steps ===== */
.info__steps {
    list-style: none;
    padding: 0;
    counter-reset: step;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.info__steps li {
    font-size: 0.95rem;
    color: var(--text-secondary);
    padding-left: 36px;
    position: relative;
    counter-increment: step;
    line-height: 1.55;
}

.info__steps li::before {
    content: counter(step);
    position: absolute;
    left: 0;
    top: 2px;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--accent);
    color: #fff;
    font-size: 0.75rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ===== FAQ ===== */
.faq {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.faq__item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: border-color var(--transition-smooth);
}

.faq__item:hover {
    border-color: #3B4559;
}

.faq__item[open] {
    border-color: var(--accent);
}

.faq__question {
    padding: 16px 20px;
    font-family: var(--font-body);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-primary);
    cursor: pointer;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

.faq__question::-webkit-details-marker {
    display: none;
}

.faq__question::after {
    content: '+';
    font-size: 1.2rem;
    font-weight: 400;
    color: var(--text-muted);
    transition: transform var(--transition-smooth);
    flex-shrink: 0;
    margin-left: 12px;
}

.faq__item[open] .faq__question::after {
    content: '−';
    color: var(--accent);
}

.faq__answer {
    padding: 0 20px 16px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ===== Footer ===== */
.footer {
    border-top: 1px solid var(--border-color);
    padding: 20px 24px;
    text-align: center;
}

.footer__inner {
    max-width: var(--max-width-content);
    margin: 0 auto;
}

.footer p {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .tool__container {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .card__textarea {
        min-height: 200px;
    }

    .hero {
        padding: 32px 16px 24px;
    }

    .hero__title {
        font-size: 1.5rem;
    }

    .hero__subtitle {
        font-size: 0.95rem;
    }

    .tool__actions {
        gap: 8px;
    }

    .btn {
        padding: 9px 14px;
        font-size: 0.8rem;
    }

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

    .info__block h2 {
        font-size: 1.25rem;
    }

    .card {
        padding: 16px 14px 12px;
    }

    .card__stats {
        gap: 8px 12px;
    }

    .stat {
        font-size: 0.72rem;
    }
}

@media (max-width: 480px) {
    .tool {
        padding: 0 12px 24px;
    }

    .card__textarea {
        min-height: 160px;
        font-size: 0.85rem;
    }

    .tool__actions {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        justify-content: center;
    }

    .hero {
        padding: 24px 12px 16px;
    }

    .header {
        padding: 12px 16px;
    }

    .logo__text {
        font-size: 1.1rem;
    }
}