/*
   BASE64 ENCODER DECODER — EXPERT WEB TOOLS
*/

@font-face { font-family: 'Inter';       src: url('/fonts/inter-v20-latin-regular.woff2') format('woff2');       font-weight: 400; font-display: swap; }
@font-face { font-family: 'Orbitron';    src: url('/fonts/orbitron-v35-latin-700.woff2') format('woff2');        font-weight: 700; font-display: swap; }
@font-face { font-family: 'Roboto Mono'; src: url('/fonts/roboto-mono-v31-latin-regular.woff2') format('woff2'); font-weight: 400; font-display: swap; }

:root {
    --bg-dark:          #0a0a0f;
    --primary-accent:   #3b82f6;
    --secondary-accent: #8b5cf6;
    --text-main:        #ffffff;
    --text-muted:       #94a3b8;
    --card-bg:          rgba(25, 25, 35, 0.6);
    --card-border:      rgba(255, 255, 255, 0.08);
    --input-bg:         rgba(0, 0, 0, 0.3);
    --font-heading:     'Orbitron', sans-serif;
    --font-body:        'Inter', sans-serif;
    --font-code:        'Roboto Mono', monospace;
}

/* Light Theme Variables (Synchronized Architecture) */
html.light-theme {
    --bg-dark:          #f8fafc;
    --primary-accent:   #2563eb;
    --secondary-accent: #7c3aed;
    --text-main:        #0f172a;
    --text-muted:       #475569;
    --card-bg:          #ffffff;
    --card-border:      #cbd5e1;
    --input-bg:         #f1f5f9;
}

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

html, body {
    width: 100%;
    max-width: 100vw;
}

/* STRICT CHROMIUM BUG FIX: transition background-color only */
html, body {
    background-color: var(--bg-dark);
    transition: background-color 0.2s ease;
}

body {
    color: var(--text-main);
    font-family: var(--font-body);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.background-glow {
    position: fixed; top: -50%; left: -50%; width: 200%; height: 200%;
    background: radial-gradient(circle at center, rgba(59, 130, 246, 0.08) 0%, rgba(10, 10, 15, 0) 50%);
    z-index: -1; pointer-events: none; transition: background 0.3s;
}
html.light-theme .background-glow {
    background: radial-gradient(circle at center, rgba(37,99,235,0.05) 0%, rgba(248,250,252,0) 50%);
}

.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border-width: 0; }

/* ── Header ─────────────────────────────────────────────────────────── */
.tool-header { display: flex; justify-content: space-between; align-items: center; padding: 1.5rem 5%; max-width: 1400px; margin: 0 auto; width: 100%; }
.header-actions { display: flex; align-items: center; gap: 1rem; }
.back-btn { color: var(--text-muted); text-decoration: none; display: flex; align-items: center; gap: 8px; transition: color 0.3s; }
.back-btn:hover { color: var(--primary-accent); }
.back-btn:focus-visible { outline: 2px solid var(--primary-accent); border-radius: 4px; }
.logo { font-family: var(--font-heading); font-size: 1.2rem; }
.logo span { color: var(--primary-accent); }

/* Sync'd Theme Toggle Button */
.theme-toggle-btn { 
    background: transparent; border: 1px solid var(--card-border); 
    color: var(--text-main); width: 36px; height: 36px; border-radius: 8px; 
    cursor: pointer; display: flex; align-items: center; justify-content: center; 
    transition: all 0.2s ease; 
}
.theme-toggle-btn:hover { border-color: var(--primary-accent); color: var(--primary-accent); }

/* ── Main Layout ────────────────────────────────────────────────────── */
.main-content { flex-grow: 1; padding: 2rem clamp(1rem, 5%, 5%); max-width: 1200px; margin: 0 auto; width: 100%; }
.tool-intro { text-align: center; margin-bottom: 2rem; }
.tool-intro h1 { font-family: var(--font-heading); font-size: clamp(1.4rem, 4vw, 2rem); margin-bottom: 0.5rem; }
.tool-intro p  { color: var(--text-muted); }

.card { background: var(--card-bg); border: 1px solid var(--card-border); border-radius: 16px; padding: 1.5rem; width: 100%; min-width: 0; }

/* ── Mode Tabs ───────────────────────────────────────────────────────── */
.tabs-nav {
    display: flex; gap: 10px; margin-bottom: 1.5rem; border-bottom: 1px solid var(--card-border); padding-bottom: 1rem;
    overflow-x: auto; scrollbar-width: none; -ms-overflow-style: none;
}
.tabs-nav::-webkit-scrollbar { display: none; }

.tab-btn {
    background: transparent; border: none; color: var(--text-muted); padding: 10px 20px; font-family: var(--font-heading); font-size: 0.9rem;
    cursor: pointer; border-radius: 8px; transition: background 0.2s, color 0.2s; white-space: nowrap; display: flex; align-items: center; gap: 8px; flex-shrink: 0;
}
.tab-btn i { flex-shrink: 0; }
.tab-btn:hover  { color: var(--text-main); background: rgba(150,150,150,0.1); }
.tab-btn.active { background: var(--primary-accent); color: #fff; }
.tab-btn:focus-visible { outline: 2px solid var(--primary-accent); }

.tool-pane { display: none; animation: fadeIn 0.3s ease; }
.tool-pane.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

/* ── UI Elements ─────────────────────────────────────────────────────── */
.settings-row { margin-bottom: 1rem; display: flex; align-items: center; flex-wrap: wrap; gap: 10px; }
.io-grid { display: grid; grid-template-columns: 1fr auto 1fr; gap: 1.5rem; align-items: stretch; min-width: 0; }
.io-column { display: flex; flex-direction: column; min-width: 0; }
.action-column { display: flex; flex-direction: column; justify-content: center; gap: 1rem; flex-shrink: 0; }
.pane-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; flex-wrap: wrap; gap: 8px; }
.pane-header label { font-size: 0.85rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; }

textarea {
    flex-grow: 1; background: var(--input-bg); border: 1px solid var(--card-border); color: var(--text-main);
    padding: 1rem; border-radius: 8px; font-family: var(--font-code); font-size: 16px; resize: vertical; min-height: 350px; outline: none; line-height: 1.5;
    width: 100%; min-width: 0; transition: border-color 0.2s, background 0.2s, color 0.2s;
}
textarea:focus { border-color: var(--primary-accent); }
textarea:focus-visible { outline: 2px solid var(--primary-accent); }
textarea[readonly] { cursor: default; }
textarea.error { border-color: #ef4444; color: #fca5a5; }
html.light-theme textarea.error { color: #dc2626; }

/* ── File Mode Additions ──────────────────────────────────────────────── */
.file-mode-selector { display: flex; gap: 1.5rem; margin-bottom: 1.5rem; border-bottom: 1px solid var(--card-border); padding-bottom: 1rem; flex-wrap: wrap; }
.radio-label { display: flex; align-items: center; gap: 8px; cursor: pointer; color: var(--text-muted); transition: color 0.2s; }
.radio-label:hover { color: var(--text-main); }
.radio-label input[type="radio"] { accent-color: var(--primary-accent); width: 18px; height: 18px; flex-shrink: 0; cursor: pointer; }
.radio-label span { font-weight: 500; }
.radio-label input[type="radio"]:checked + span { color: var(--primary-accent); }

.file-grid { display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1.5fr); gap: 2rem; align-items: start; min-width: 0; }
.upload-section { display: flex; flex-direction: column; gap: 1rem; min-width: 0; }
.output-section { display: flex; flex-direction: column; min-width: 0; }

.drop-area {
    border: 2px dashed var(--card-border); border-radius: 12px; padding: 3rem 1rem; text-align: center; cursor: pointer;
    transition: border-color 0.2s, background 0.2s; background: rgba(255,255,255,0.02);
}
html.light-theme .drop-area { background: rgba(0,0,0,0.02); }
.drop-area:hover, .drop-area.dragover { border-color: var(--primary-accent); background: rgba(59,130,246,0.05); }
.drop-area:focus-visible { outline: 2px solid var(--primary-accent); border-radius: 12px; }
.pointer-events-none { pointer-events: none; }
.upload-icon { font-size: 3rem; color: var(--secondary-accent); margin-bottom: 1rem; display: block; }
.drop-area h3 { font-family: var(--font-heading); font-size: 1.1rem; margin-bottom: 5px; }
.drop-area p { color: var(--text-muted); font-size: 0.9rem; margin-top: 4px; }

.file-info { display: flex; justify-content: space-between; align-items: center; background: var(--input-bg); border: 1px solid var(--card-border); padding: 12px 15px; border-radius: 8px; gap: 10px; min-width: 0; overflow: hidden; }
.file-details { display: flex; align-items: center; gap: 10px; min-width: 0; overflow: hidden; flex: 1; }
.text-green { color: #10b981; flex-shrink: 0; }
#fileNameDisplay { font-size: 0.9rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; min-width: 0; }
.badge { background: rgba(150,150,150,0.2); font-size: 0.75rem; padding: 2px 6px; border-radius: 4px; color: var(--text-main); white-space: nowrap; flex-shrink: 0; }
.danger-badge { background: rgba(239,68,68,0.2); color: #ef4444; }

.settings-box { background: rgba(0,0,0,0.2); border: 1px solid var(--card-border); padding: 1rem; border-radius: 8px; }
html.light-theme .settings-box { background: rgba(0,0,0,0.03); }
.toggle-checkbox { display: flex; align-items: flex-start; gap: 8px; color: var(--text-main); font-size: 0.95rem; cursor: pointer; user-select: none; flex-wrap: wrap; }
.toggle-checkbox span { color: var(--text-muted); font-size: 0.85em; }
.toggle-checkbox input { accent-color: var(--primary-accent); cursor: pointer; width: 16px; height: 16px; flex-shrink: 0; margin-top: 2px; font-size: 16px; }
.toggle-checkbox code { font-family: var(--font-code); font-size: 0.85em; color: var(--secondary-accent); word-break: break-all; }

.overhead-stats { font-size: 0.85rem; color: var(--text-muted); padding-top: 0.5rem; border-top: 1px solid var(--card-border); }
.overhead-stats strong { color: var(--text-main); }

.hex-preview { background: rgba(0,0,0,0.3); border: 1px solid var(--card-border); border-radius: 8px; padding: 1rem; }
html.light-theme .hex-preview { background: #e2e8f0; }
.hex-preview h5 { margin-bottom: 8px; color: var(--text-muted); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 1px; }
.hex-preview code { font-family: var(--font-code); color: var(--secondary-accent); word-break: break-all; font-size: 0.9rem; }

/* ── Buttons ─────────────────────────────────────────────────────────── */
.primary-btn { background: var(--primary-accent); color: #fff; border: none; padding: 12px 20px; border-radius: 8px; font-weight: 600; cursor: pointer; transition: background 0.2s; font-family: var(--font-body); display: flex; align-items: center; justify-content: center; gap: 8px; white-space: nowrap; }
.primary-btn:hover { background: #2563eb; }
.primary-btn:focus-visible { outline: 2px solid var(--text-main); outline-offset: 2px; }

.secondary-btn { background: transparent; color: var(--text-main); border: 1px solid var(--card-border); padding: 12px 20px; border-radius: 8px; font-weight: 600; cursor: pointer; transition: background 0.2s, border-color 0.2s; font-family: var(--font-body); display: flex; align-items: center; justify-content: center; gap: 8px; white-space: nowrap; }
.secondary-btn:hover { background: rgba(150,150,150,0.1); border-color: var(--text-muted); }
.secondary-btn:focus-visible { outline: 2px solid var(--primary-accent); }

.success-btn { background: #10b981; color: #fff; border: none; padding: 12px 20px; border-radius: 8px; font-weight: 600; cursor: pointer; transition: background 0.2s; font-family: var(--font-body); display: flex; align-items: center; justify-content: center; gap: 8px; }
.success-btn:hover { background: #059669; }
.success-btn:focus-visible { outline: 2px solid var(--text-main); outline-offset: 2px; }

.icon-btn { background: transparent; border: none; color: var(--text-muted); cursor: pointer; font-size: 1.1rem; transition: color 0.2s; padding: 6px; border-radius: 6px; line-height: 1; flex-shrink: 0; }
.icon-btn:hover { color: var(--primary-accent); }
.icon-btn.danger:hover { color: #ef4444; }
.icon-btn:focus-visible { outline: 2px solid var(--primary-accent); border-radius: 6px; }

.action-group { display: flex; gap: 10px; }

/* ── Utilities ───────────────────────────────────────────────────────── */
.hidden { display: none !important; }
.mt-half { margin-top: 0.5rem; }
.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mb-half { margin-bottom: 0.5rem; }
.hint { font-size: 0.8rem; color: var(--text-muted); margin-top: 8px; line-height: 1.4; }

/* ── Toast (FIXED WRAPPING) ──────────────────────────────────────────── */
.toast {
    display: block; position: fixed; bottom: 20px; left: 50%; transform: translateX(-50%);
    background: #1e1e24; border: 1px solid var(--primary-accent); color: #fff;
    padding: 12px 20px; border-radius: 8px; z-index: 2000;
    box-shadow: 0 4px 12px rgba(0,0,0,0.5); transition: opacity 0.3s;
    font-size: 0.9rem; pointer-events: none; text-align: center;
    width: max-content; max-width: calc(100vw - 2rem);
    white-space: normal; word-break: break-word;
    opacity: 0;
}
html.light-theme .toast { background: #1e293b; color: #f8fafc; border-color: var(--card-border); }
.toast.toast-visible { opacity: 1; pointer-events: auto; }
.toast.error { border-color: #ef4444; color: #fca5a5; }

/* ── Info Section ────────────────────────────────────────────────────── */
.info-section { margin-top: 4rem; padding: 0 1rem; }
.info-section h2 { font-family: var(--font-heading); color: var(--text-main); margin-bottom: 2rem; font-size: 1.5rem; text-align: center; }
.info-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 2rem; margin-bottom: 2rem; }
.info-grid h3  { color: var(--primary-accent); font-family: var(--font-heading); font-size: 1.1rem; margin-bottom: 0.5rem; }
.info-grid i   { margin-right: 8px; }
.info-grid p   { color: var(--text-muted); font-size: 0.95rem; line-height: 1.6; }

.faq-container { margin-top: 2rem; }
.faq-container h3 { font-family: var(--font-heading); color: var(--text-main); margin: 1.5rem 0 1rem; }
.faq-container h4 { color: var(--secondary-accent); font-size: 1rem; margin-bottom: 0.5rem; margin-top: 1.5rem; }
.faq-container p  { color: var(--text-muted); font-size: 0.95rem; margin-bottom: 1rem; line-height: 1.6; }

footer { text-align: center; padding: 3rem 0; color: var(--text-muted); font-size: 0.9rem; border-top: 1px solid var(--card-border); margin-top: 3rem; }
footer a { color: var(--text-main); text-decoration: none; }
footer a:hover { color: var(--primary-accent); }

@media (prefers-reduced-motion: reduce) { *, *::before, *::after { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; } }

/* ═══════════════════════════════════════════════════════════════════════
   RESPONSIVE BREAKPOINTS
   ═══════════════════════════════════════════════════════════════════════ */

@media (max-width: 900px) {
    .io-grid { grid-template-columns: 1fr; gap: 1rem; }
    .action-column { flex-direction: row; }
    .action-column button { flex: 1; }
    textarea { min-height: 200px; }
    .file-grid { grid-template-columns: 1fr; gap: 1.5rem; }
}

@media (max-width: 600px) {
    .tool-header, .main-content { padding: 1rem; }
    .card { padding: 1rem; border-radius: 12px; }
    .tab-btn { padding: 8px 14px; font-size: 0.82rem; }
    textarea { min-height: 160px; font-size: 14px; padding: 0.75rem; }
    .pane-header { margin-bottom: 8px; }
    .drop-area { padding: 2rem 0.75rem; }
    .upload-icon { font-size: 2.2rem; }
    .toggle-checkbox { font-size: 0.88rem; }
    .info-section { padding: 0; }
    .info-grid { grid-template-columns: 1fr; }
    .toast { font-size: 0.85rem; padding: 10px 16px; }
}

@media (max-width: 380px) {
    .tool-intro h1 { font-size: 1.2rem; }
    .card { padding: 0.75rem; }
    .tab-btn { padding: 8px 10px; font-size: 0.78rem; }
    textarea { min-height: 130px; }
    .primary-btn, .secondary-btn { padding: 10px 14px; font-size: 0.9rem; }
}