/* ===== DESIGN TOKENS ===== */
:root {
  --accent: #10b981;
  --accent-hover: #059669;
  --accent-soft: rgba(16, 185, 129, 0.12);
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.12);
  --shadow-lg: 0 8px 40px rgba(0,0,0,0.2);
  --transition: 0.22s cubic-bezier(0.4,0,0.2,1);
  --font: 'Inter', system-ui, sans-serif;
}

[data-theme="dark"] {
  --bg: #0d0f12;
  --bg-card: #161a20;
  --bg-card2: #1c2028;
  --border: rgba(255,255,255,0.07);
  --text: #f0f4f8;
  --text-muted: #8b95a1;
  --text-soft: #c5ced8;
  --input-bg: #1c2028;
  --pill-bg: rgba(16,185,129,0.12);
}

[data-theme="light"] {
  --bg: #f4f7fb;
  --bg-card: #ffffff;
  --bg-card2: #f0f4f8;
  --border: rgba(0,0,0,0.07);
  --text: #111827;
  --text-muted: #6b7280;
  --text-soft: #374151;
  --input-bg: #f9fafb;
  --pill-bg: rgba(16,185,129,0.1);
}

/* ===== RESET ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--font);background:var(--bg);color:var(--text);min-height:100vh;transition:background var(--transition),color var(--transition);line-height:1.6}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
button{cursor:pointer;font-family:var(--font)}

/* ===== NAVBAR ===== */
.navbar{position:sticky;top:0;z-index:100;display:flex;align-items:center;justify-content:space-between;padding:0 2rem;height:60px;background:var(--bg-card);border-bottom:1px solid var(--border);backdrop-filter:blur(12px)}
.nav-brand{display:flex;align-items:center;gap:10px}
.nav-logo{display:flex;align-items:center}
.nav-title{font-size:1.1rem;font-weight:700;color:var(--text)}
.nav-actions{display:flex;align-items:center;gap:10px}

.history-btn,.theme-toggle{display:flex;align-items:center;justify-content:center;width:38px;height:38px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-card2);color:var(--text-muted);transition:all var(--transition);position:relative}
.history-btn:hover,.theme-toggle:hover{background:var(--accent-soft);color:var(--accent);border-color:var(--accent)}
.history-count{position:absolute;top:-5px;right:-5px;background:var(--accent);color:#fff;font-size:10px;font-weight:700;border-radius:50%;width:18px;height:18px;display:flex;align-items:center;justify-content:center}
.nav-pdf-tools-btn{display:flex;align-items:center;gap:6px;padding:7px 13px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--bg-card2);color:var(--text-muted);font-size:0.82rem;font-weight:600;transition:all var(--transition)}
.nav-pdf-tools-btn:hover{background:var(--accent-soft);color:var(--accent);border-color:var(--accent)}

[data-theme="dark"] .sun-icon{display:none}
[data-theme="light"] .moon-icon{display:none}

/* ===== HERO ===== */
.hero{text-align:center;padding:4rem 2rem 2rem;max-width:800px;margin:0 auto}
.hero-badge{display:inline-flex;align-items:center;gap:8px;padding:6px 14px;border-radius:999px;background:var(--accent-soft);border:1px solid rgba(16,185,129,0.25);color:var(--accent);font-size:0.78rem;font-weight:600;margin-bottom:1.4rem;letter-spacing:0.04em}
.badge-dot{width:7px;height:7px;border-radius:50%;background:var(--accent);animation:pulse 2s infinite}
@keyframes pulse{0%,100%{opacity:1;transform:scale(1)}50%{opacity:0.5;transform:scale(1.3)}}
.hero-title{font-size:clamp(2rem,5vw,3.2rem);font-weight:800;line-height:1.15;letter-spacing:-0.02em;margin-bottom:1rem}
.accent-text{color:var(--accent)}
.hero-sub{color:var(--text-muted);font-size:1.05rem;margin-bottom:2rem;max-width:560px;margin-left:auto;margin-right:auto}

.format-pills{display:flex;flex-wrap:wrap;gap:8px;justify-content:center;margin-bottom:1rem}
.pill{padding:5px 14px;border-radius:999px;background:var(--pill-bg);border:1px solid rgba(16,185,129,0.2);color:var(--accent);font-size:0.78rem;font-weight:600;letter-spacing:0.05em;transition:transform var(--transition)}
.pill:hover{transform:translateY(-2px)}

/* ===== MAIN CONTAINER ===== */
.main-container{max-width:780px;margin:0 auto;padding:0 1.5rem 2rem}


/* ===== UPLOAD CARD ===== */
.upload-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:2px;box-shadow:var(--shadow);margin-bottom:1.5rem;overflow:hidden}
.drop-zone{border:2px dashed var(--border);border-radius:calc(var(--radius) - 2px);padding:3rem 2rem;text-align:center;transition:all var(--transition);cursor:pointer;position:relative}
.drop-zone.drag-over{border-color:var(--accent);background:var(--accent-soft);transform:scale(1.01)}
.drop-icon{display:flex;justify-content:center;margin-bottom:1rem;color:var(--text-muted);transition:color var(--transition)}
.drop-zone:hover .drop-icon,.drop-zone.drag-over .drop-icon{color:var(--accent)}
.drop-title{font-size:1.05rem;font-weight:600;color:var(--text);margin-bottom:0.4rem}
.drop-sub{font-size:0.82rem;color:var(--text-muted);margin-bottom:1.2rem;max-width:420px;margin-left:auto;margin-right:auto}
.browse-btn{padding:10px 24px;border-radius:var(--radius-sm);border:2px solid var(--accent);background:var(--accent-soft);color:var(--accent);font-weight:600;font-size:0.9rem;transition:all var(--transition)}
.browse-btn:hover{background:var(--accent);color:#fff}

/* ===== FILE QUEUE ===== */
.file-queue{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);margin-bottom:1.5rem}
.queue-header{display:flex;align-items:center;justify-content:space-between;padding:1rem 1.25rem;border-bottom:1px solid var(--border)}
.queue-title{display:flex;align-items:center;gap:8px;font-size:0.95rem;font-weight:600;color:var(--text)}
.clear-all-btn{padding:5px 12px;border-radius:6px;border:1px solid var(--border);background:transparent;color:var(--text-muted);font-size:0.8rem;cursor:pointer;transition:all var(--transition)}
.clear-all-btn:hover{border-color:#ef4444;color:#ef4444}

/* ===== QUEUE ITEM ===== */
.queue-list{max-height:320px;overflow-y:auto}
.queue-item{display:grid;grid-template-columns:auto 1fr auto auto;gap:12px;align-items:center;padding:14px 1.25rem;border-bottom:1px solid var(--border);transition:background var(--transition)}
.queue-item:last-child{border-bottom:none}
.queue-item:hover{background:var(--bg-card2)}
.file-icon{width:36px;height:36px;border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:0.7rem;font-weight:700;flex-shrink:0}
.file-info{min-width:0}
.file-name{font-size:0.9rem;font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:var(--text)}
.file-size{font-size:0.78rem;color:var(--text-muted)}
.item-format-select{padding:5px 8px;border-radius:6px;border:1px solid var(--border);background:var(--input-bg);color:var(--text);font-size:0.78rem;max-width:110px;cursor:pointer;outline:none;transition:border-color var(--transition)}
.item-format-select:focus{border-color:var(--accent)}
.remove-item-btn{width:28px;height:28px;border-radius:6px;border:none;background:transparent;color:var(--text-muted);display:flex;align-items:center;justify-content:center;transition:all var(--transition);font-size:1rem;flex-shrink:0}
.remove-item-btn:hover{background:rgba(239,68,68,0.1);color:#ef4444}

/* ===== PROGRESS BAR ===== */
.item-progress{grid-column:1/-1;height:3px;background:var(--border);border-radius:2px;overflow:hidden;display:none}
.item-progress.active{display:block}
.item-progress-bar{height:100%;background:var(--accent);border-radius:2px;width:0%;transition:width 0.4s ease}
.item-status{grid-column:1/-1;font-size:0.78rem;color:var(--text-muted);display:none}
.item-status.active{display:block}
.item-status.success{color:var(--accent)}
.item-status.error{color:#ef4444}
.download-link{display:none;align-items:center;gap:5px;padding:5px 10px;border-radius:6px;background:var(--accent);color:#fff;font-size:0.78rem;font-weight:600;text-decoration:none;transition:background var(--transition)}
.download-link:hover{background:var(--accent-hover);text-decoration:none}
.download-link.active{display:flex}

/* ===== GLOBAL FORMAT ===== */
.global-format{display:flex;align-items:center;gap:12px;padding:1rem 1.25rem;border-top:1px solid var(--border);flex-wrap:wrap}
.format-label{font-size:0.85rem;font-weight:600;color:var(--text);white-space:nowrap}
.format-select-wrapper{position:relative;flex:1;min-width:160px;max-width:220px}
.format-select{width:100%;padding:8px 12px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--input-bg);color:var(--text);font-size:0.85rem;outline:none;cursor:pointer;transition:border-color var(--transition)}
.format-select:focus{border-color:var(--accent)}
.or-divider{font-size:0.78rem;color:var(--text-muted)}

/* ===== CONVERT BUTTON ===== */
.convert-btn{width:calc(100% - 2.5rem);margin:0 1.25rem 1.25rem;display:flex;align-items:center;justify-content:center;gap:10px;padding:13px;border-radius:var(--radius-sm);border:none;background:var(--accent);color:#fff;font-size:1rem;font-weight:700;letter-spacing:0.02em;transition:all var(--transition);box-shadow:0 4px 20px rgba(16,185,129,0.3)}
.convert-btn:hover:not(:disabled){background:var(--accent-hover);transform:translateY(-1px);box-shadow:0 6px 28px rgba(16,185,129,0.4)}
.convert-btn:disabled{opacity:0.4;cursor:not-allowed;transform:none;box-shadow:none}
.convert-btn.loading{background:var(--accent-hover);pointer-events:none}

/* ===== STATS BAR ===== */
.stats-bar{display:grid;grid-template-columns:repeat(4,1fr);gap:0;background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}
.stat-item{padding:1.2rem 1rem;text-align:center}
.stat-number{display:block;font-size:1.4rem;font-weight:800;color:var(--accent);line-height:1}
.stat-label{font-size:0.75rem;color:var(--text-muted);margin-top:4px}
.stat-divider{width:1px;background:var(--border)}

/* ===== FEATURES ===== */
.features-section{max-width:900px;margin:3rem auto;padding:0 1.5rem}
.section-title{text-align:center;font-size:1.6rem;font-weight:800;margin-bottom:2rem;color:var(--text)}
.features-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:1rem}
.feature-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:1.5rem;transition:all var(--transition)}
.feature-card:hover{border-color:var(--accent);transform:translateY(-3px);box-shadow:var(--shadow-lg)}
.feature-icon{font-size:2rem;margin-bottom:0.75rem}
.feature-card h3{font-size:0.95rem;font-weight:700;color:var(--text);margin-bottom:0.5rem}
.feature-card p{font-size:0.82rem;color:var(--text-muted);line-height:1.6}

/* ===== HISTORY PANEL ===== */
.history-overlay{position:fixed;inset:0;background:rgba(0,0,0,0.5);z-index:200;opacity:0;pointer-events:none;transition:opacity var(--transition)}
.history-overlay.open{opacity:1;pointer-events:all}
.history-panel{position:fixed;right:-400px;top:0;width:360px;height:100vh;background:var(--bg-card);border-left:1px solid var(--border);z-index:201;display:flex;flex-direction:column;transition:right var(--transition);overflow:hidden}
.history-panel.open{right:0}
.history-header{display:flex;align-items:center;justify-content:space-between;padding:1.2rem 1.25rem;border-bottom:1px solid var(--border);flex-shrink:0}
.history-header h3{font-size:1rem;font-weight:700}
.history-header-actions{display:flex;align-items:center;gap:8px}
.clear-history-btn{padding:5px 10px;border-radius:6px;border:1px solid var(--border);background:transparent;color:var(--text-muted);font-size:0.78rem;cursor:pointer;transition:all var(--transition)}
.clear-history-btn:hover{border-color:#ef4444;color:#ef4444}
.close-history-btn{width:32px;height:32px;border-radius:6px;border:1px solid var(--border);background:transparent;color:var(--text-muted);cursor:pointer;font-size:1rem;transition:all var(--transition)}
.close-history-btn:hover{background:var(--bg-card2)}
.history-list{flex:1;overflow-y:auto;padding:1rem 1.25rem;display:flex;flex-direction:column;gap:10px}
.empty-history{text-align:center;color:var(--text-muted);font-size:0.85rem;margin-top:2rem}
.history-item{background:var(--bg-card2);border:1px solid var(--border);border-radius:var(--radius-sm);padding:12px}
.history-item-name{font-size:0.85rem;font-weight:600;color:var(--text);margin-bottom:3px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.history-item-meta{font-size:0.75rem;color:var(--text-muted)}
.history-item-badge{display:inline-block;padding:2px 8px;border-radius:999px;background:var(--accent-soft);color:var(--accent);font-size:0.7rem;font-weight:700;margin-top:6px}


/* ===== TOASTS ===== */
.toast-container{position:fixed;bottom:1.5rem;right:1.5rem;z-index:400;display:flex;flex-direction:column;gap:10px;max-width:340px}
.toast{display:flex;align-items:center;gap:10px;padding:13px 16px;border-radius:var(--radius-sm);background:var(--bg-card);border:1px solid var(--border);box-shadow:var(--shadow-lg);font-size:0.85rem;font-weight:500;animation:slideInRight 0.3s ease;color:var(--text)}
@keyframes slideInRight{from{opacity:0;transform:translateX(30px)}to{opacity:1;transform:translateX(0)}}
.toast.success{border-color:rgba(16,185,129,0.4);background:var(--accent-soft);color:var(--accent)}
.toast.error{border-color:rgba(239,68,68,0.3);background:rgba(239,68,68,0.08);color:#ef4444}
.toast.info{border-color:rgba(59,130,246,0.3);background:rgba(59,130,246,0.08);color:#3b82f6}
.toast-dismiss{margin-left:auto;background:transparent;border:none;cursor:pointer;color:inherit;opacity:0.6;font-size:1rem}

/* ===== FOOTER ===== */
.footer{text-align:center;padding:2rem;color:var(--text-muted);font-size:0.82rem;border-top:1px solid var(--border);margin-top:3rem}

/* ===== FILE TYPE COLORS ===== */
.type-pdf{background:rgba(239,68,68,0.12);color:#ef4444}
.type-word{background:rgba(59,130,246,0.12);color:#3b82f6}
.type-excel{background:rgba(16,185,129,0.12);color:var(--accent)}
.type-ppt{background:rgba(245,158,11,0.12);color:#f59e0b}
.type-image{background:rgba(168,85,247,0.12);color:#a855f7}
.type-ebook{background:rgba(236,72,153,0.12);color:#ec4899}
.type-other{background:rgba(107,114,128,0.12);color:#6b7280}

/* ===== PDF TOOLS SECTION ===== */
.pdf-tools-section{max-width:780px;margin:2.5rem auto;padding:0 1.5rem}
.pdf-tools-header{display:flex;align-items:flex-start;justify-content:space-between;flex-wrap:wrap;gap:12px;margin-bottom:1.5rem}
.pdf-tools-sub{font-size:0.85rem;color:var(--text-muted);margin-top:0.25rem}
.pdf-tools-badge{display:inline-flex;align-items:center;gap:6px;padding:5px 12px;border-radius:999px;background:var(--accent-soft);border:1px solid rgba(16,185,129,0.25);color:var(--accent);font-size:0.75rem;font-weight:600;white-space:nowrap;align-self:flex-start}
.pdf-tabs{display:flex;gap:6px;margin-bottom:1.2rem;background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius-sm);padding:4px;width:fit-content}
.pdf-tab{display:flex;align-items:center;gap:7px;padding:8px 16px;border-radius:calc(var(--radius-sm) - 2px);border:none;background:transparent;color:var(--text-muted);font-size:0.85rem;font-weight:600;cursor:pointer;transition:all var(--transition)}
.pdf-tab.active{background:var(--accent);color:#fff;box-shadow:0 2px 8px rgba(16,185,129,0.3)}
.pdf-tab:not(.active):hover{background:var(--bg-card2);color:var(--text)}
.pdf-panel{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow)}
.pdf-drop-zone{display:flex;flex-direction:column;align-items:center;gap:8px;padding:2rem 1.5rem;border:2px dashed var(--border);margin:1rem;border-radius:calc(var(--radius) - 4px);cursor:pointer;transition:all var(--transition);color:var(--text-muted);text-align:center}
.pdf-drop-zone:hover,.pdf-drop-zone.drag-over{border-color:var(--accent);background:var(--accent-soft);color:var(--accent)}
.pdf-drop-zone p{font-size:0.95rem;font-weight:600;color:var(--text)}
.pdf-drop-zone:hover p,.pdf-drop-zone.drag-over p{color:var(--accent)}
.pdf-drop-hint{font-size:0.78rem;color:var(--text-muted)}
.merge-list{padding:0 1rem 0.5rem}
.merge-list-header{display:flex;align-items:center;justify-content:space-between;padding:0.5rem 0;margin-bottom:0.5rem;font-size:0.82rem;color:var(--text-muted);font-weight:600}
.merge-item{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:var(--radius-sm);background:var(--bg-card2);border:1px solid var(--border);margin-bottom:6px;cursor:grab;transition:all var(--transition);user-select:none}
.merge-item:hover{border-color:var(--accent)}
.merge-item.dragging{opacity:0.5;border-color:var(--accent);cursor:grabbing}
.merge-item.drag-over-item{border-top:2px solid var(--accent)}
.merge-drag-handle{color:var(--text-muted);font-size:1.1rem;flex-shrink:0}
.merge-item-name{flex:1;font-size:0.85rem;font-weight:500;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:var(--text)}
.merge-item-size{font-size:0.75rem;color:var(--text-muted);flex-shrink:0}
.merge-remove-btn{width:24px;height:24px;border-radius:4px;border:none;background:transparent;color:var(--text-muted);cursor:pointer;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:all var(--transition)}
.merge-remove-btn:hover{background:rgba(239,68,68,0.1);color:#ef4444}
.merge-hint{font-size:0.75rem;color:var(--text-muted);text-align:center;padding:4px 0 10px}
.split-options{padding:1rem 1.25rem}
.split-file-info{font-size:0.82rem;color:var(--accent);font-weight:600;background:var(--accent-soft);border:1px solid rgba(16,185,129,0.25);padding:8px 12px;border-radius:var(--radius-sm);margin-bottom:1.2rem}
.split-mode-label{display:block;font-size:0.82rem;font-weight:600;color:var(--text);margin-bottom:10px}
.split-modes{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-bottom:1.2rem}
@media(max-width:600px){.split-modes{grid-template-columns:1fr}}
.radio-card{display:flex;flex-direction:column;gap:3px;padding:12px;border-radius:var(--radius-sm);border:1.5px solid var(--border);cursor:pointer;transition:all var(--transition);position:relative}
.radio-card input[type="radio"]{position:absolute;opacity:0;pointer-events:none}
.radio-card:has(input:checked){border-color:var(--accent);background:var(--accent-soft)}
.radio-title{font-size:0.85rem;font-weight:600;color:var(--text)}
.radio-card:has(input:checked) .radio-title{color:var(--accent)}
.radio-desc{font-size:0.75rem;color:var(--text-muted);line-height:1.4}
.split-range-input{margin-bottom:1.2rem}
.range-text-input{width:100%;padding:9px 12px;border-radius:var(--radius-sm);border:1px solid var(--border);background:var(--input-bg);color:var(--text);font-size:0.88rem;outline:none;transition:border-color var(--transition);font-family:var(--font)}
.range-text-input:focus{border-color:var(--accent)}
.range-hint{font-size:0.75rem;color:var(--text-muted);display:block;margin-top:5px}

/* ===== SCROLLBAR ===== */

::-webkit-scrollbar{width:5px;height:5px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:3px}

/* ===== RESPONSIVE ===== */
@media(max-width:640px){
  .navbar{padding:0 1rem}
  .nav-pdf-tools-btn span{display:none} /* hide label on mobile, keep icon */
  .hero{padding:2.5rem 1rem 1.5rem}
  .stats-bar{grid-template-columns:repeat(2,1fr)}
  .stat-divider{display:none}
  .queue-item{grid-template-columns:auto 1fr auto}
  .item-format-select{display:none}
  .history-panel{width:100%;right:-100%}
  .global-format{gap:8px}
}