:root {
    --bg-page: #FAFAFA;
    --bg-surface: #FFFFFF;
    --bg-surface-hover: #F3F4F6;
    --border-color: #E5E7EB;
    --border-focus: #000000;

    --text-primary: #111827;
    --text-secondary: #6B7280;
    --text-tertiary: #9CA3AF;

    --accent: #000000;
    --accent-hover: #374151;
    --success: #10B981;
    --error: #EF4444;
    --warning: #F59E0B;

    --ring: rgba(0, 0, 0, 0.08);
    --ring-focus: rgba(0, 0, 0, 0.15);

    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-elevated: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background-color: var(--bg-page);
    color: var(--text-primary);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
}

/* Typography */
.headline { font-size: 2.5rem; font-weight: 700; letter-spacing: -0.03em; margin-bottom: 0.5rem; text-align: center; }
.subheadline { font-size: 1.125rem; color: var(--text-secondary); text-align: center; margin-bottom: 3rem; }
.mono-text { font-family: 'JetBrains Mono', monospace; }

/* Navigation */
.navbar { border-bottom: 1px solid var(--border-color); background: var(--bg-surface); padding: 1rem 0; }
.nav-content { max-width: 1000px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 0 1.5rem; }
.brand { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 1.125rem; letter-spacing: -0.02em; }

/* Layout */
.workspace { max-width: 800px; margin: 4rem auto; padding: 0 1.5rem; }

/* Components */
.card { background: var(--bg-surface); border: 1px solid var(--border-color); border-radius: var(--radius-lg); box-shadow: var(--shadow-md); overflow: hidden; transition: box-shadow 0.3s; }
.card:focus-within { box-shadow: var(--shadow-elevated); }

/* URL Input Area */
.input-wrapper { display: flex; align-items: center; padding: 0.5rem; background: var(--bg-surface); border-bottom: 1px solid transparent; position: relative; z-index: 10;}
.input-icon { padding: 0 1rem; color: var(--text-tertiary); display: flex; align-items: center; }
.premium-input { flex: 1; border: none; font-size: 1.125rem; padding: 1rem 0; color: var(--text-primary); background: transparent; }
.premium-input:focus { outline: none; }
.premium-input::placeholder { color: var(--text-tertiary); }

/* Buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 0.75rem 1.5rem; font-weight: 500; font-size: 0.875rem; border-radius: var(--radius-sm); cursor: pointer; transition: all 0.2s; border: 1px solid transparent; white-space: nowrap; }
.btn.primary { background: var(--accent); color: white; box-shadow: var(--shadow-sm); }
.btn.primary:hover { background: var(--accent-hover); transform: translateY(-1px); }
.btn.primary:active { transform: translateY(0); }
.btn.secondary { background: var(--bg-surface); color: var(--text-primary); border-color: var(--border-color); }
.btn.secondary:hover { background: var(--bg-surface-hover); }
.btn:disabled { opacity: 0.6; cursor: not-allowed; transform: none !important; }
.full-width { width: 100%; }

.icon-btn { background: transparent; border: none; color: var(--text-secondary); padding: 0.75rem; cursor: pointer; border-radius: var(--radius-sm); transition: all 0.2s; display: flex; align-items: center; margin-right: 0.5rem; }
.icon-btn:hover { background: var(--bg-surface-hover); color: var(--text-primary); }

/* Advanced Options Panel */
.options-panel { background: #F9FAFB; border-top: 1px solid var(--border-color); padding: 1.5rem; display: grid; transition: all 0.3s ease-in-out; max-height: 500px; opacity: 1; overflow: hidden;}
.options-panel.collapsed { max-height: 0; opacity: 0; padding-top: 0; padding-bottom: 0; border-top-color: transparent; }
.options-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; }
@media (max-width: 600px) { .options-grid { grid-template-columns: 1fr; } }

.form-group label { display: block; font-size: 0.875rem; font-weight: 500; margin-bottom: 0.5rem; }
.badge { display: inline-block; font-size: 0.7rem; font-weight: 600; text-transform: uppercase; background: var(--border-color); padding: 2px 6px; border-radius: 4px; margin-left: 6px; color: var(--text-secondary); }
.helper-text { font-size: 0.75rem; color: var(--text-secondary); margin-top: 0.5rem; display: flex; align-items: center; gap: 4px; }
.helper-text.warning { color: var(--warning); font-weight: 500; }

.elegant-input { width: 100%; padding: 0.75rem; border: 1px solid var(--border-color); border-radius: var(--radius-sm); font-size: 0.875rem; font-family: inherit; transition: all 0.2s; background: var(--bg-surface); }
.elegant-input:focus { outline: none; border-color: var(--border-focus); box-shadow: 0 0 0 3px var(--ring-focus); }

.slug-input-wrapper { display: flex; align-items: center; border: 1px solid var(--border-color); border-radius: var(--radius-sm); background: var(--bg-surface); overflow: hidden; transition: all 0.2s;}
.slug-input-wrapper:focus-within { border-color: var(--border-focus); box-shadow: 0 0 0 3px var(--ring-focus); }
.slug-prefix { padding: 0.75rem 0.25rem 0.75rem 0.75rem; color: var(--text-tertiary); font-size: 0.875rem; user-select: none; }
.slug-input-wrapper .elegant-input { border: none; padding-left: 0.25rem; box-shadow: none; }

/* Result State */
.state-view { display: block; animation: fadeIn 0.3s ease-out; }
.state-view.hidden { display: none; }

.result-header { text-align: center; padding: 2rem 2rem 1rem; }
.success-icon { display: inline-flex; align-items: center; justify-content: center; width: 48px; height: 48px; border-radius: 50%; background: #D1FAE5; color: var(--success); margin-bottom: 1rem; }
.result-header h2 { font-size: 1.5rem; font-weight: 600; letter-spacing: -0.02em; }

.result-url-box { margin: 0 2rem; padding: 1.5rem; background: var(--bg-page); border: 1px dashed var(--border-color); border-radius: var(--radius-md); text-align: center; }
.result-url-box a { font-size: 1.25rem; color: var(--accent); text-decoration: none; font-weight: 500; transition: opacity 0.2s;}
.result-url-box a:hover { opacity: 0.7; }

.result-meta { text-align: center; font-size: 0.875rem; color: var(--text-secondary); margin: 1.5rem 2rem; display: flex; align-items: center; justify-content: center; gap: 8px; }
.truncate { max-width: 250px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; display: inline-block; }

.result-actions { padding: 1.5rem 2rem 2rem; display: grid; grid-template-columns: 2fr 1fr; gap: 1rem; border-top: 1px solid var(--border-color); background: #F9FAFB; }
@media (max-width: 500px) { .result-actions { grid-template-columns: 1fr; } }

/* Toast Notifications */
#toast-container { position: fixed; bottom: 2rem; right: 2rem; display: flex; flex-direction: column; gap: 0.5rem; z-index: 100; }
.toast { background: var(--text-primary); color: white; padding: 12px 20px; border-radius: var(--radius-sm); font-size: 0.875rem; font-weight: 500; box-shadow: var(--shadow-elevated); animation: slideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards; display: flex; align-items: center; gap: 8px;}
.toast.error { background: var(--error); }
.toast.fade-out { animation: fadeOut 0.3s forwards; }

@keyframes fadeIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }
@keyframes slideIn { from { transform: translateY(100%) scale(0.95); opacity: 0; } to { transform: translateY(0) scale(1); opacity: 1; } }
@keyframes fadeOut { to { opacity: 0; transform: scale(0.95); } }