:root {
    --primary-grad: linear-gradient(135deg, #f59e0b, #ef4444);
    --primary-color: #f59e0b;
    --primary-glow: rgba(245, 158, 11, 0.3);
    --secondary-grad: linear-gradient(135deg, #6366f1, #a855f7);
    --bg-dark: #0f172a;
    --card-bg: rgba(255, 255, 255, 0.08);
    --card-border: rgba(255, 255, 255, 0.1);
    --text-white: #ffffff;
    --text-dim: #94a3b8;
    --success: #10b981;
    --danger: #ef4444;
    --font-main: 'Outfit', 'Inter', system-ui, sans-serif;
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-dark);
    color: var(--text-white);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    overflow-x: hidden;
    position: relative;
    padding: 20px 0;
}

/* Background Glowing Orbs */
.background-decor {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    z-index: -1;
    opacity: 0.35;
    animation: pulse 15s infinite alternate ease-in-out;
}

.blob-1 {
    top: -10%;
    left: -10%;
    width: 60vw;
    height: 60vw;
    background: radial-gradient(circle, #f59e0b, #ef4444);
}

.blob-2 {
    bottom: -10%;
    right: -10%;
    width: 50vw;
    height: 50vw;
    background: radial-gradient(circle, #6366f1, #a855f7);
}

@keyframes pulse {
    0% { transform: scale(1) translate(0, 0); }
    100% { transform: scale(1.1) translate(30px, 30px); }
}

.back-link {
    position: absolute;
    top: 20px;
    left: 20px;
    z-index: 1000;
    padding: 12px 20px;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(12px);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    color: white;
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s;
}

.back-link:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateX(-5px);
}

.container {
    width: 95%;
    max-width: 700px;
    background: var(--card-bg);
    backdrop-filter: blur(25px);
    -webkit-backdrop-filter: blur(25px);
    border: 1px solid var(--card-border);
    border-radius: 32px;
    padding: 2.5rem 2rem;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    text-align: center;
}

h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
    background: var(--primary-grad);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -1px;
}

.subtitle {
    color: var(--text-dim);
    font-size: 0.95rem;
    margin-bottom: 2rem;
    font-weight: 500;
}

/* ============================================
   Drop Zone
   ============================================ */
.drop-zone {
    border: 2px dashed rgba(245, 158, 11, 0.3);
    border-radius: 24px;
    padding: 3rem 2rem;
    background: rgba(245, 158, 11, 0.03);
    transition: all 0.3s ease;
    cursor: pointer;
    position: relative;
}

.drop-zone.drag-over {
    border-color: var(--primary-color);
    background: rgba(245, 158, 11, 0.08);
    transform: scale(1.01);
    box-shadow: 0 0 40px var(--primary-glow);
}

.drop-zone-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.8rem;
    pointer-events: none;
}

.drop-zone-content > label {
    pointer-events: auto;
}

.drop-icon {
    font-size: 3rem;
    color: var(--primary-color);
    opacity: 0.7;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.drop-text {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-white);
}

.drop-subtext {
    font-size: 0.85rem;
    color: var(--text-dim);
}

.file-select-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 0.7rem 1.5rem;
    background: var(--primary-grad);
    color: white;
    border: none;
    border-radius: 14px;
    font-weight: 700;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 6px 20px var(--primary-glow);
}

.file-select-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 30px var(--primary-glow);
}

.supported-formats {
    font-size: 0.75rem;
    color: var(--text-dim);
    opacity: 0.6;
    margin-top: 0.3rem;
}

/* ============================================
   Settings Panel
   ============================================ */
.settings-panel {
    display: none;
    margin-top: 1.5rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    animation: slideIn 0.3s ease;
}

.settings-panel.visible {
    display: block;
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.settings-row {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
    flex-wrap: wrap;
}

.setting-group {
    flex: 1;
    min-width: 180px;
    text-align: left;
}

.setting-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-dim);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.7rem;
}

.format-selector {
    display: flex;
    gap: 0.5rem;
}

.format-btn {
    flex: 1;
    padding: 0.6rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    color: var(--text-dim);
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.3s;
    font-family: var(--font-main);
}

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

.format-btn.active {
    background: var(--primary-grad);
    color: white;
    border-color: transparent;
    box-shadow: 0 4px 15px var(--primary-glow);
}

/* Quality Slider */
.quality-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
    outline: none;
    margin-top: 4px;
}

.quality-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-grad);
    cursor: pointer;
    box-shadow: 0 2px 10px var(--primary-glow);
    transition: transform 0.2s;
}

.quality-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.quality-slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 10px var(--primary-glow);
}

#quality-group {
    transition: opacity 0.3s;
}

#quality-group.hidden {
    opacity: 0.3;
    pointer-events: none;
}

/* ============================================
   File List
   ============================================ */
.file-list {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    margin-top: 1.5rem;
}

.file-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.2rem;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    transition: all 0.3s;
    animation: slideIn 0.3s ease;
}

.file-item:hover {
    background: rgba(255, 255, 255, 0.07);
}

.file-thumb {
    width: 48px;
    height: 48px;
    border-radius: 10px;
    object-fit: cover;
    flex-shrink: 0;
    background: rgba(255, 255, 255, 0.05);
}

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

.file-name {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-white);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.file-meta {
    font-size: 0.75rem;
    color: var(--text-dim);
    margin-top: 2px;
}

.file-status {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    flex-shrink: 0;
}

.file-status.ready {
    color: var(--text-dim);
}

.file-status.converting {
    color: var(--primary-color);
}

.file-status.done {
    color: var(--success);
}

.file-status.error {
    color: var(--danger);
}

.file-actions {
    display: flex;
    gap: 0.4rem;
    flex-shrink: 0;
}

.icon-btn {
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid transparent;
    color: var(--text-dim);
    width: 36px;
    height: 36px;
    border-radius: 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    transition: all 0.3s;
}

.icon-btn:hover {
    background: rgba(255, 255, 255, 0.12);
    color: var(--text-white);
}

.icon-btn.download-btn:hover {
    color: var(--success);
    border-color: rgba(16, 185, 129, 0.3);
}

.icon-btn.remove-btn:hover {
    color: var(--danger);
    border-color: rgba(239, 68, 68, 0.3);
}

/* Progress spinner */
.spinner {
    width: 18px;
    height: 18px;
    border: 2px solid rgba(245, 158, 11, 0.2);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ============================================
   Action Bar
   ============================================ */
.action-bar {
    display: none;
    gap: 0.8rem;
    margin-top: 1.5rem;
    flex-wrap: wrap;
}

.action-bar.visible {
    display: flex;
}

.primary-btn {
    flex: 1;
    padding: 1rem 1.5rem;
    border-radius: 16px;
    border: none;
    background: var(--primary-grad);
    color: white;
    font-weight: 800;
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    box-shadow: 0 8px 25px var(--primary-glow);
    font-family: var(--font-main);
}

.primary-btn:hover:not(:disabled) {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px var(--primary-glow);
}

.primary-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.secondary-btn {
    flex: 1;
    padding: 1rem 1.5rem;
    border-radius: 16px;
    border: 1px solid rgba(16, 185, 129, 0.3);
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    transition: all 0.3s;
    font-family: var(--font-main);
}

.secondary-btn:hover {
    background: rgba(16, 185, 129, 0.2);
    transform: translateY(-2px);
}

.clear-btn {
    padding: 1rem 1.2rem;
    border-radius: 16px;
    border: 1px solid rgba(239, 68, 68, 0.2);
    background: rgba(239, 68, 68, 0.05);
    color: var(--text-dim);
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: all 0.3s;
    font-family: var(--font-main);
}

.clear-btn:hover {
    background: rgba(239, 68, 68, 0.15);
    color: var(--danger);
    border-color: rgba(239, 68, 68, 0.4);
}

/* ============================================
   Footer
   ============================================ */
footer {
    margin-top: 2.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--card-border);
    text-align: center;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

footer p {
    color: var(--text-dim);
    font-size: 0.9rem;
    margin: 0;
}

.version {
    font-size: 0.85rem;
    color: var(--text-dim);
    opacity: 0.6;
    font-weight: 600;
}

/* ============================================
   Toast
   ============================================ */
.toast {
    position: fixed;
    bottom: -50px;
    left: 50%;
    transform: translateX(-50%);
    background: white;
    color: var(--bg-dark);
    padding: 12px 24px;
    border-radius: 50px;
    font-weight: 600;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    z-index: 2000;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.toast.show {
    bottom: 30px;
}

/* ============================================
   Tab Bar
   ============================================ */
.tab-bar {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    padding: 6px;
}

.tab-btn {
    flex: 1;
    padding: 0.65rem 1rem;
    border: none;
    border-radius: 12px;
    background: transparent;
    color: var(--text-dim);
    font-weight: 700;
    font-size: 0.88rem;
    cursor: pointer;
    transition: all 0.3s;
    font-family: var(--font-main);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
}

.tab-btn:hover {
    color: var(--text-white);
    background: rgba(255, 255, 255, 0.06);
}

.tab-btn.active {
    background: var(--primary-grad);
    color: white;
    box-shadow: 0 4px 15px var(--primary-glow);
}

/* ============================================
   PDF Section
   ============================================ */
.pdf-file-info {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    padding: 0.8rem 1rem;
    background: rgba(239, 68, 68, 0.06);
    border: 1px solid rgba(239, 68, 68, 0.2);
    border-radius: 14px;
    font-size: 0.9rem;
}

.pdf-file-name-text {
    flex: 1;
    font-weight: 600;
    color: var(--text-white);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.pdf-page-badge {
    font-size: 0.78rem;
    font-weight: 700;
    color: var(--text-dim);
    background: rgba(255, 255, 255, 0.07);
    padding: 3px 10px;
    border-radius: 20px;
    white-space: nowrap;
    flex-shrink: 0;
}

/* Page input fields */
.page-input-row {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    margin-top: 0.8rem;
}

.page-number-input {
    flex: 1;
    padding: 0.55rem 0.8rem;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    color: var(--text-white);
    font-size: 0.9rem;
    font-family: var(--font-main);
    outline: none;
    transition: border-color 0.2s;
    -moz-appearance: textfield;
}

.page-number-input::-webkit-outer-spin-button,
.page-number-input::-webkit-inner-spin-button {
    -webkit-appearance: none;
}

.page-number-input:focus {
    border-color: var(--primary-color);
}

.page-input-sep {
    color: var(--text-dim);
    font-weight: 600;
    font-size: 0.9rem;
}

.page-text-input {
    width: 100%;
    padding: 0.55rem 0.8rem;
    background: rgba(255, 255, 255, 0.06);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    color: var(--text-white);
    font-size: 0.9rem;
    font-family: var(--font-main);
    outline: none;
    transition: border-color 0.2s;
}

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

.page-text-input::placeholder,
.page-number-input::placeholder {
    color: rgba(148, 163, 184, 0.4);
}

/* Progress Bar */
.progress-bar-wrap {
    text-align: center;
}

.progress-bar-track {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    width: 0%;
    background: var(--primary-grad);
    border-radius: 4px;
    transition: width 0.3s ease;
    box-shadow: 0 0 10px var(--primary-glow);
}

.progress-text {
    margin-top: 0.7rem;
    font-size: 0.85rem;
    color: var(--text-dim);
    font-weight: 600;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 600px) {
    .back-link {
        top: 10px;
        left: 10px;
        font-size: 11px;
        padding: 8px 12px;
    }

    .container {
        padding: 2rem 1.2rem;
        margin-top: 60px;
        margin-bottom: 20px;
        border-radius: 24px;
    }

    h1 {
        font-size: 2rem;
    }

    .drop-zone {
        padding: 2rem 1rem;
    }

    .drop-icon {
        font-size: 2.2rem;
    }

    .settings-row {
        flex-direction: column;
        gap: 1.2rem;
    }

    .file-item {
        flex-wrap: wrap;
        gap: 0.6rem;
    }

    .file-info {
        flex-basis: calc(100% - 60px);
    }

    .file-status {
        order: 3;
        flex-basis: 100%;
    }

    .file-actions {
        order: 4;
        flex-basis: 100%;
        justify-content: flex-end;
    }

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

    .footer-content {
        flex-direction: column;
        gap: 0.5rem;
    }
}