:root {
  --bg: #0F172A;
  --bg-card: #1e293b;
  --bg-card-hover: #263548;
  --bg-input: #0f172a;
  --bg-overlay: rgba(0,0,0,0.5);
  --text: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accept: #10B981;
  --accept-bg: rgba(16,185,129,0.1);
  --reject: #EF4444;
  --reject-bg: rgba(239,68,68,0.1);
  --edit: #6C63FF;
  --edit-bg: rgba(108,99,255,0.1);
  --both: #f59e0b;
  --both-bg: rgba(245,158,11,0.1);
  --border: rgba(108,99,255,0.12);
  --border-strong: rgba(108,99,255,0.25);
  --shadow: 0 4px 14px rgba(0,0,0,0.4);
  --radius: 6px;
  --font: 'Inter',-apple-system,sans-serif;
  --mono: 'JetBrains Mono','Fira Code',monospace;
  --transition: 0.2s ease;
  --glass: rgba(30,41,59,0.85);
  --line-add: rgba(16,185,129,0.12);
  --line-remove: rgba(239,68,68,0.12);
  --line-change: rgba(245,158,11,0.08);
}

[data-theme="light"] {
  --bg: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-input: #ffffff;
  --text: #1e293b;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --border: rgba(108,99,255,0.15);
  --border-strong: rgba(108,99,255,0.3);
  --shadow: 0 4px 14px rgba(0,0,0,0.08);
  --glass: rgba(255,255,255,0.85);
  --line-add: rgba(16,185,129,0.08);
  --line-remove: rgba(239,68,68,0.08);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:16px}
body{font-family:var(--font);background:var(--bg);color:var(--text);min-height:100vh;transition:background var(--transition),color var(--transition)}

.header{position:sticky;top:0;z-index:100;background:var(--glass);backdrop-filter:blur(14px);border-bottom:1px solid var(--border);height:52px}
.header-inner{max-width:1200px;margin:0 auto;padding:0 20px;height:100%;display:flex;align-items:center;justify-content:space-between;gap:10px}
.logo{display:flex;align-items:center;gap:8px}
.logo-icon{font-size:1.2rem}
.logo h1{font-size:1.1rem;font-weight:700;color:var(--accept)}
.header-actions{display:flex;align-items:center;gap:6px}

.btn{display:inline-flex;align-items:center;gap:5px;padding:6px 12px;border:none;border-radius:var(--radius);font-family:var(--font);font-size:0.78rem;font-weight:500;cursor:pointer;transition:all var(--transition);white-space:nowrap}
.btn-primary{background:linear-gradient(135deg,var(--accept),#059669);color:#fff}
.btn-primary:hover{transform:translateY(-1px);box-shadow:var(--shadow)}
.btn-ghost{background:transparent;color:var(--text-secondary);border:1px solid var(--border)}
.btn-ghost:hover{background:var(--bg-card);border-color:var(--border-strong)}
.btn-ghost:disabled{opacity:0.35;cursor:default}
.btn-accept{background:var(--accept-bg);color:var(--accept);border:1px solid rgba(16,185,129,0.3)}
.btn-accept:hover{background:rgba(16,185,129,0.2)}
.btn-reject{background:var(--reject-bg);color:var(--reject);border:1px solid rgba(239,68,68,0.3)}
.btn-reject:hover{background:rgba(239,68,68,0.2)}
.btn-both{background:var(--both-bg);color:var(--both);border:1px solid rgba(245,158,11,0.3)}
.btn-both:hover{background:rgba(245,158,11,0.2)}
.btn-edit{background:var(--edit-bg);color:var(--edit);border:1px solid rgba(108,99,255,0.3)}
.btn-edit:hover{background:rgba(108,99,255,0.2)}

.icon-btn{display:flex;align-items:center;justify-content:center;width:32px;height:32px;border:1px solid var(--border);border-radius:var(--radius);background:transparent;color:var(--text-secondary);cursor:pointer;transition:all var(--transition)}
.icon-btn:hover{background:var(--bg-card);color:var(--edit)}
.icon-btn svg{width:14px;height:14px}

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

.conflict-nav{display:flex;align-items:center;gap:4px}
.nav-text{font-size:0.75rem;color:var(--text-muted);font-family:var(--mono);min-width:40px;text-align:center}

.main{max-width:1200px;margin:0 auto;padding:16px 20px}

/* Input View */
.input-card{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:24px;transition:border var(--transition)}
.input-card.drag-over{border-color:var(--edit);background:var(--edit-bg)}
.input-header{margin-bottom:14px}
.input-header h2{font-size:1.2rem;font-weight:700;margin-bottom:4px}
.input-header p{font-size:0.82rem;color:var(--text-muted)}
.input-header code{background:rgba(108,99,255,0.1);padding:1px 5px;border-radius:3px;font-size:0.78rem;color:var(--edit);font-family:var(--mono)}

#conflict-input{width:100%;padding:14px;border:1px solid var(--border);border-radius:var(--radius);background:var(--bg-input);color:var(--text);font-family:var(--mono);font-size:0.82rem;resize:vertical;min-height:200px;line-height:1.5;transition:border var(--transition)}
#conflict-input:focus{outline:none;border-color:var(--edit)}

.input-actions{display:flex;gap:8px;margin-top:14px}

/* Diff View */
.diff-view{animation:fadeIn .3s ease}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

.conflict-block{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);margin-bottom:16px;overflow:hidden}
.conflict-header{display:flex;align-items:center;justify-content:space-between;padding:12px 16px;border-bottom:1px solid var(--border);flex-wrap:wrap;gap:8px}
.conflict-header h3{font-size:0.85rem;font-weight:600}
.conflict-actions{display:flex;gap:6px;flex-wrap:wrap}

.split-pane{display:grid;grid-template-columns:1fr 2px 1fr;min-height:120px}
.pane{overflow-x:auto}
.pane-header{padding:6px 14px;font-size:0.72rem;font-weight:600;text-transform:uppercase;letter-spacing:.05em;color:var(--text-muted);border-bottom:1px solid var(--border)}
.pane-left .pane-header{background:var(--line-add)}
.pane-right .pane-header{background:var(--line-remove)}
.pane-divider{background:var(--border-strong)}
.pane-code{padding:10px 14px;font-family:var(--mono);font-size:0.8rem;line-height:1.6;white-space:pre-wrap;word-wrap:break-word;margin:0;min-height:60px;color:var(--text)}

.line-added{background:var(--line-add)}
.line-removed{background:var(--line-remove)}
.line-changed{background:var(--line-change)}

.edit-area{padding:12px 16px;border-top:1px solid var(--border)}
#edit-textarea{width:100%;padding:10px;border:1px solid var(--edit);border-radius:var(--radius);background:var(--bg-input);color:var(--text);font-family:var(--mono);font-size:0.82rem;resize:vertical;min-height:100px;margin-bottom:8px}
#edit-textarea:focus{outline:none;box-shadow:0 0 0 3px rgba(108,99,255,0.15)}

.output-section{background:var(--bg-card);border:1px solid var(--border);border-radius:var(--radius);padding:16px}
.output-section h3{font-size:0.85rem;font-weight:600;margin-bottom:10px}
.output-code{font-family:var(--mono);font-size:0.8rem;line-height:1.6;white-space:pre-wrap;word-wrap:break-word;padding:14px;background:var(--bg-input);border-radius:var(--radius);border:1px solid var(--border);max-height:400px;overflow-y:auto;margin:0;color:var(--text)}

.toast-container{position:fixed;bottom:20px;right:20px;z-index:2000;display:flex;flex-direction:column;gap:6px}
.toast{padding:10px 16px;background:var(--bg-card);border:1px solid var(--border-strong);border-radius:var(--radius);box-shadow:var(--shadow);font-size:0.82rem;color:var(--text);animation:toastIn .3s ease,toastOut .3s ease 2.7s forwards;max-width:280px}
@keyframes toastIn{from{opacity:0;transform:translateX(16px)}to{opacity:1;transform:translateX(0)}}
@keyframes toastOut{from{opacity:1}to{opacity:0;transform:translateX(16px)}}

@media(max-width:768px){
  .split-pane{grid-template-columns:1fr}
  .pane-divider{height:2px;width:100%}
  .conflict-header{flex-direction:column;align-items:flex-start}
  .conflict-actions{width:100%}
  .header-actions{flex-wrap:wrap}
}