:root,
[data-theme="dark"] {
    --bg-primary: #060906;
    --bg-secondary: #0b100b;
    --bg-tertiary: #111811;
    --bg-hover: #162216;
    --border-color: #1e2d1e;
    --text-primary: #e2f0e2;
    --text-secondary: #8aad8a;
    --text-muted: #4a644a;
    --accent-primary: #39ff14;
    --accent-secondary: #2dd60d;
    --accent-success: #39ff14;
    --accent-warning: #f5a623;
    --accent-danger: #ff4545;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.85);
    --glow: 0 0 16px rgba(57, 255, 20, 0.25);
    --glow-strong: 0 0 28px rgba(57, 255, 20, 0.4);
    --msg-sent-bg: #0f2e0f;
    --msg-sent-text: #c8f5c0;
    --msg-sent-meta: rgba(200, 245, 192, 0.5);
    --card-bg: rgba(11, 16, 11, 0.75);
    --card-border: rgba(57, 255, 20, 0.09);
    --card-border-hover: rgba(57, 255, 20, 0.22);
}

[data-theme="light"] {
    --bg-primary: #f0f4f0;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e6ece6;
    --bg-hover: #d8e4d8;
    --border-color: #c8d8c8;
    --text-primary: #111a11;
    --text-secondary: #335533;
    --text-muted: #667a66;
    --accent-primary: #0a7a00;
    --accent-secondary: #087000;
    --accent-success: #0a7a00;
    --accent-warning: #b87800;
    --accent-danger: #c42020;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    --glow: none;
    --glow-strong: none;
    --msg-sent-bg: #0a7a00;
    --msg-sent-text: #ffffff;
    --msg-sent-meta: rgba(255, 255, 255, 0.75);
    --card-bg: rgba(255, 255, 255, 0.9);
    --card-border: rgba(0, 100, 0, 0.12);
    --card-border-hover: rgba(0, 100, 0, 0.28);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { height: 100%; }

body {
    height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

/* Monospace only where it matters */
code, .chat-session-value, .resume-info code, .invite-input,
.form-group input[readonly], .session-timer, .msg-rate-counter,
.alias-bar input, .alias-bar label { font-family: 'Courier New', Courier, monospace; }

#app { min-height: 100%; display: flex; flex-direction: column; }

.page { display: none; flex-direction: column; min-height: 100vh; }
.page.active { display: flex; animation: fadeIn 0.3s ease forwards; }

#chat.page.active {
    height: 100vh; min-height: unset;
    overflow: hidden; animation: none;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}
@keyframes messageAppear {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}
.message-appear { animation: messageAppear 0.25s ease forwards; }

/* ── Header ─────────────────────────────────────────────── */
header {
    padding: 1.75rem 2rem;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
    position: relative;
    transition: background-color 0.3s, border-color 0.3s;
}

.header-content {
    display: flex; align-items: center; justify-content: space-between;
    max-width: 1200px; margin: 0 auto;
}
.header-left, .header-right { width: 90px; display: flex; align-items: center; }
.header-right { justify-content: flex-end; gap: 0.5rem; }
.header-center { flex: 1; text-align: center; }

.github-link { color: var(--text-muted); transition: color 0.2s; }
.github-link:hover { color: var(--accent-primary); }

.btn-theme {
    background: none; border: 1px solid var(--border-color); border-radius: 6px;
    padding: 0.4rem; cursor: pointer; color: var(--text-muted);
    transition: color 0.2s, border-color 0.2s, background-color 0.2s;
    display: flex; align-items: center; justify-content: center;
}
.btn-theme:hover { color: var(--accent-primary); border-color: var(--accent-primary); background-color: var(--bg-hover); }

header h1 {
    font-size: 2.6rem; font-weight: 800; margin-bottom: 0.3rem;
    letter-spacing: 0.18em; text-transform: uppercase;
    font-family: 'Courier New', Courier, monospace;
    color: var(--accent-primary);
}
[data-theme="light"] header h1 {
    color: var(--accent-primary);
}

header h2 { font-size: 1.4rem; font-weight: 600; }
.tagline { color: var(--text-muted); font-size: 0.85rem; letter-spacing: 0.06em; text-transform: uppercase; margin-top: 0.15rem; }

/* ── Landing page ────────────────────────────────────────── */
main { flex: 1; padding: 2rem 2rem; max-width: 960px; margin: 0 auto; width: 100%; }
.landing-content { display: flex; flex-direction: column; gap: 2.25rem; }

.hero {
    padding: 0.25rem 0 0;
    display: flex; flex-direction: column; align-items: center;
    text-align: center;
}

.hero-lead {
    font-size: 0.95rem; color: var(--text-secondary);
    line-height: 1.75; margin-bottom: 1.25rem;
    max-width: 560px;
}

.actions {
    display: flex; flex-direction: column; gap: 0.6rem;
    max-width: 300px; width: 100%;
}

.resume-session {
    display: flex; align-items: center; justify-content: space-between;
    gap: 0.75rem; padding: 0.7rem 1rem;
    background-color: var(--bg-secondary); border: 1px solid var(--border-color);
    border-radius: 6px; font-size: 0.8rem;
}
.resume-session.hidden { display: none; }
.resume-info { display: flex; align-items: center; gap: 0.5rem; color: var(--text-secondary); min-width: 0; }
.resume-info svg { flex-shrink: 0; color: var(--accent-primary); }
.resume-info code { color: var(--accent-primary); font-size: 0.78rem; word-break: break-all; }
.resume-actions { display: flex; align-items: center; gap: 0.4rem; flex-shrink: 0; }
.btn-resume { padding: 0.3rem 0.75rem; font-size: 0.78rem; }
.btn-clear-session {
    background: none; border: 1px solid var(--border-color); border-radius: 6px;
    padding: 0.3rem; cursor: pointer; color: var(--text-muted);
    display: flex; align-items: center; transition: color 0.2s, border-color 0.2s;
}
.btn-clear-session:hover { color: var(--accent-danger); border-color: var(--accent-danger); }

/* ── Features ────────────────────────────────────────────── */
.features {
    display: grid; grid-template-columns: repeat(2, 1fr);
    gap: 0 2.5rem;
    border-top: 1px solid var(--border-color);
}

.feature {
    display: flex; align-items: flex-start; gap: 0.7rem;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.feature-icon {
    flex-shrink: 0; color: var(--accent-primary);
    opacity: 0.7; margin-top: 2px;
}

.feature-body { min-width: 0; }
.feature h3 {
    font-size: 0.85rem; font-weight: 600; margin-bottom: 0.2rem;
    color: var(--text-primary);
}
.feature p { color: var(--text-secondary); font-size: 0.82rem; line-height: 1.55; }

/* ── Buttons ─────────────────────────────────────────────── */
.btn-primary, .btn-secondary {
    padding: 0.75rem 1.5rem; font-size: 0.9rem; font-weight: 600; font-family: inherit;
    border: none; border-radius: 6px; cursor: pointer;
    transition: background-color 0.15s, border-color 0.15s;
    width: 100%;
}
.btn-primary {
    background: var(--accent-primary);
    color: #041004;
}
.btn-primary:hover:not(:disabled) {
    background: #4dff28;
}
[data-theme="light"] .btn-primary { color: #fff; background: var(--accent-primary); }
[data-theme="light"] .btn-primary:hover:not(:disabled) { background: var(--accent-secondary); }
.btn-primary:disabled { opacity: 0.45; cursor: not-allowed; transform: none; }

.btn-secondary {
    background: var(--bg-secondary); color: var(--text-primary);
    border: 1px solid var(--border-color);
}
.btn-secondary:hover {
    background-color: var(--bg-hover); border-color: var(--accent-primary);
}

.btn-back {
    background: none; border: none; color: var(--accent-primary); cursor: pointer;
    font-size: 0.9rem; font-family: inherit; padding: 0.5rem 1rem;
    position: absolute; left: 1rem; top: 50%; transform: translateY(-50%);
    transition: all 0.2s ease; letter-spacing: 0.03em;
}
.btn-back:hover { opacity: 0.75; }

.btn-icon {
    background: none; border: 1px solid var(--border-color); border-radius: 6px;
    padding: 0.5rem; cursor: pointer; font-size: 0.8rem; font-family: inherit;
    color: var(--text-muted); transition: color 0.2s, border-color 0.2s, background-color 0.2s;
    display: flex; align-items: center; justify-content: center;
    min-width: 34px; min-height: 34px;
}
.btn-icon:hover { background-color: var(--bg-hover); border-color: var(--accent-primary); color: var(--accent-primary); }

/* ── Transparency / Limitations section ──────────────────── */
.transparency {
    padding: 0;
    transition: background-color 0.3s;
}
#landing.active .transparency { animation: fadeIn 0.5s ease 0.2s both; }
.transparency h3 {
    font-size: 0.82rem; font-weight: 600; margin-bottom: 0.9rem;
    color: var(--text-secondary);
}
.transparency ul { list-style: none; display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.3rem 2.5rem; }
.transparency li {
    color: var(--text-secondary); font-size: 0.82rem; padding: 0.2rem 0 0.2rem 1rem;
    position: relative;
}
.transparency li::before { content: "–"; position: absolute; left: 0; color: var(--text-muted); }

/* ── Footer ──────────────────────────────────────────────── */
footer {
    padding: 1.25rem; text-align: center;
    border-top: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
    transition: background-color 0.3s;
}
footer p { color: var(--text-muted); font-size: 0.82rem; }
footer a { color: var(--text-muted); text-decoration: none; transition: color 0.2s; }
footer a:hover { color: var(--accent-primary); }

/* ── Forms ───────────────────────────────────────────────── */
.form-group { margin-bottom: 1.5rem; }
.form-group label {
    display: block; margin-bottom: 0.5rem; font-weight: 600;
    color: var(--text-primary); font-size: 0.85rem; letter-spacing: 0.03em;
}
.form-group input {
    width: 100%; padding: 0.8rem 1rem; font-size: 0.95rem; font-family: inherit;
    background-color: var(--bg-tertiary); border: 1px solid var(--border-color);
    border-radius: 8px; color: var(--text-primary); -webkit-appearance: none; appearance: none;
    transition: background-color 0.3s, border-color 0.2s, color 0.3s, box-shadow 0.2s;
}
.form-group input:focus {
    outline: none; border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(57,255,20,0.1);
}
[data-theme="light"] .form-group input:focus { box-shadow: 0 0 0 3px rgba(0,100,0,0.1); }
.form-group input[readonly] { background-color: var(--bg-secondary); color: var(--text-secondary); }
.input-with-action { display: flex; gap: 0.5rem; }
.input-with-action input { flex: 1; }
.hint { margin-top: 0.5rem; font-size: 0.78rem; color: var(--text-muted); }
.warning-box {
    background-color: rgba(245, 166, 35, 0.08); border: 1px solid rgba(245,166,35,0.35);
    border-radius: 8px; padding: 1rem; margin-bottom: 1.5rem;
    font-size: 0.85rem; color: var(--accent-warning);
}

.remember-row { margin-bottom: 1.25rem; }
.remember-label {
    display: flex; align-items: center; gap: 0.6rem;
    cursor: pointer; font-size: 0.85rem; color: var(--text-secondary); user-select: none;
}
.remember-label input[type="checkbox"] { accent-color: var(--accent-primary); width: 15px; height: 15px; cursor: pointer; }
.remember-label span { transition: color 0.2s; }
.remember-label:hover span { color: var(--text-primary); }
.remember-hint { margin-top: 0.4rem; font-size: 0.75rem; color: var(--text-muted); padding-left: 1.6rem; line-height: 1.5; }
.remember-hint code { color: var(--text-secondary); font-size: 0.72rem; }

/* ── Password strength ───────────────────────────────────── */
.password-strength { margin-top: 0.5rem; display: flex; align-items: center; gap: 0.5rem; min-height: 20px; }
.strength-bar { height: 3px; border-radius: 2px; background-color: var(--bg-hover); flex: 1; overflow: hidden; }
.strength-fill { height: 100%; width: 0; border-radius: 2px; transition: width 0.3s, background-color 0.3s; }
.strength-label { font-size: 0.72rem; min-width: 50px; font-weight: 600; letter-spacing: 0.04em; }
.strength-weak .strength-fill { background-color: var(--accent-danger); }
.strength-weak .strength-label { color: var(--accent-danger); }
.strength-medium .strength-fill { background-color: var(--accent-warning); }
.strength-medium .strength-label { color: var(--accent-warning); }
.strength-strong .strength-fill { background-color: var(--accent-success); }
.strength-strong .strength-label { color: var(--accent-success); }

/* ── QR ──────────────────────────────────────────────────── */
.qr-container { text-align: center; margin: 1.5rem 0; }
.qr-container canvas {
    border-radius: 10px; max-width: 180px; display: inline-block;
    box-shadow: 0 0 0 10px #fff, 0 0 0 12px var(--border-color), var(--shadow);
}
.qr-label { font-size: 0.78rem; color: var(--text-muted); margin-top: 1rem; }

.modal-invite { max-width: 360px; }
.invite-qr-wrap { text-align: center; margin-bottom: 1.25rem; }
.invite-qr-wrap canvas {
    display: inline-block; border-radius: 6px; max-width: 160px;
    box-shadow: 0 0 0 6px #fff, 0 0 0 8px var(--border-color);
}
.invite-field { margin-bottom: 0.75rem; }
.invite-field-label { font-size: 0.72rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.07em; display: block; margin-bottom: 0.3rem; }
.invite-field-row { display: flex; gap: 0.4rem; }
.invite-input {
    flex: 1; padding: 0.45rem 0.65rem; font-size: 0.78rem;
    background-color: var(--bg-tertiary); border: 1px solid var(--border-color);
    border-radius: 6px; color: var(--text-secondary); min-width: 0;
}

.create-content, .join-content { max-width: 500px; margin: 2rem auto; }

/* ── Chat UI ─────────────────────────────────────────────── */
.chat-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 0.9rem 1.5rem; position: relative;
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.3s;
}
.chat-info { display: flex; align-items: center; gap: 0.5rem; }
.chat-session-label { color: var(--text-muted); font-size: 0.75rem; }
.chat-session-value {
    font-size: 0.75rem; color: var(--text-secondary);
    background-color: var(--bg-tertiary); padding: 0.2rem 0.5rem;
    border-radius: 5px; border: 1px solid var(--border-color);
}

.status-indicator { display: flex; align-items: center; gap: 0.5rem; }
.status-dot { width: 7px; height: 7px; border-radius: 50%; background-color: var(--accent-warning); transition: background-color 0.3s; }
.status-indicator.connected .status-dot { background-color: var(--accent-success); box-shadow: 0 0 6px rgba(57,255,20,0.6); }
.status-indicator.disconnected .status-dot { background-color: var(--accent-danger); }
.status-text { font-size: 0.75rem; color: var(--text-muted); }

.session-timer {
    font-size: 0.75rem; color: var(--text-muted);
    padding: 0.2rem 0.5rem; border-radius: 5px;
    background-color: var(--bg-tertiary); border: 1px solid var(--border-color);
    transition: color 0.3s;
}
.timer-warning { color: var(--accent-danger); border-color: var(--accent-danger); }

.btn-sound {
    background: none; border: 1px solid var(--border-color); border-radius: 6px;
    padding: 0.4rem; cursor: pointer; color: var(--text-muted);
    transition: color 0.2s, border-color 0.2s; display: flex; align-items: center;
}
.btn-sound:hover { color: var(--accent-primary); border-color: var(--accent-primary); }

.chat-container { display: flex; flex-direction: column; flex: 1; min-height: 0; overflow: hidden; position: relative; }

.messages-container {
    flex: 1; min-height: 0; overflow-y: auto;
    padding: 1.25rem; display: flex; flex-direction: column;
    gap: 0.7rem; overscroll-behavior: contain;
}

.message {
    max-width: 78%; padding: 0.75rem 1rem;
    border-radius: 12px; word-wrap: break-word;
    transition: background-color 0.3s;
}
.message.sent {
    align-self: flex-end;
    background-color: var(--msg-sent-bg); color: var(--msg-sent-text);
    border: 1px solid rgba(57,255,20,0.15);
    border-radius: 12px 12px 2px 12px;
}
.message.received {
    align-self: flex-start;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color); color: var(--text-primary);
    border-radius: 12px 12px 12px 2px;
}
.message-content { font-size: 0.9rem; white-space: pre-wrap; }
.message-meta { display: flex; justify-content: space-between; margin-top: 0.45rem; font-size: 0.68rem; color: var(--text-muted); }
.message.sent .message-meta { color: var(--msg-sent-meta); }
.message-alias { font-weight: 700; }
.message-error { color: var(--accent-danger); font-style: italic; }
.system-message { text-align: center; padding: 0.5rem; color: var(--text-muted); font-size: 0.78rem; }

.typing-indicator { padding: 0.5rem 1.25rem; font-size: 0.78rem; color: var(--text-muted); display: flex; align-items: center; gap: 0.5rem; }
.typing-indicator.hidden { display: none; }
.typing-dots { display: flex; gap: 3px; }
.typing-dots span { width: 6px; height: 6px; border-radius: 50%; background-color: var(--text-muted); animation: typingBounce 1.4s infinite ease-in-out both; }
.typing-dots span:nth-child(1) { animation-delay: 0s; }
.typing-dots span:nth-child(2) { animation-delay: 0.16s; }
.typing-dots span:nth-child(3) { animation-delay: 0.32s; }
@keyframes typingBounce { 0%,80%,100% { transform: scale(0.6); opacity: 0.4; } 40% { transform: scale(1); opacity: 1; } }

.scroll-to-bottom {
    position: absolute; bottom: 0.75rem; right: 1.5rem; width: 36px; height: 36px;
    border-radius: 50%; background-color: var(--accent-secondary); color: var(--bg-primary);
    border: none; cursor: pointer; display: flex; align-items: center; justify-content: center;
    opacity: 0; transform: scale(0.8); transition: opacity 0.2s, transform 0.2s;
    pointer-events: none; z-index: 10; box-shadow: 0 2px 12px rgba(0,0,0,0.5);
}
.scroll-to-bottom.visible { opacity: 1; transform: scale(1); pointer-events: auto; }
.scroll-to-bottom:hover { background-color: var(--accent-primary); box-shadow: var(--glow); }

.alias-bar {
    display: flex; align-items: center; gap: 0.5rem; padding: 0.5rem 1.25rem;
    background-color: var(--bg-secondary); border-top: 1px solid var(--border-color);
    transition: background-color 0.3s;
}
.alias-bar label { font-size: 0.75rem; color: var(--text-muted); white-space: nowrap; }
.msg-rate-counter {
    margin-left: auto; font-size: 0.68rem; color: var(--text-muted);
    opacity: 0.6; transition: color 0.3s, opacity 0.3s; white-space: nowrap;
}
.msg-rate-counter.counter-warn { color: var(--accent-warning); opacity: 1; }
.msg-rate-counter.counter-danger { color: var(--accent-danger); opacity: 1; }
.alias-bar input {
    flex: 1; max-width: 150px; padding: 0.4rem 0.75rem; font-size: 0.78rem;
    background-color: var(--bg-tertiary); border: 1px solid var(--border-color);
    border-radius: 6px; color: var(--text-primary);
    transition: background-color 0.3s, color 0.3s, border-color 0.2s;
}
.alias-bar input:focus { outline: none; border-color: var(--accent-primary); }

.message-form {
    display: flex; gap: 0.65rem; padding: 0.9rem 1.25rem;
    background-color: var(--bg-secondary); border-top: 1px solid var(--border-color);
    align-items: flex-end; transition: background-color 0.3s;
}
.btn-attach {
    background: none; border: 1px solid var(--border-color); border-radius: 8px;
    padding: 0.6rem; cursor: pointer; color: var(--text-secondary);
    transition: color 0.2s, border-color 0.2s, background-color 0.2s;
    display: flex; align-items: center; justify-content: center;
    min-width: 44px; min-height: 44px; flex-shrink: 0;
}
.btn-attach:hover:not(:disabled) { color: var(--accent-primary); border-color: var(--accent-primary); background-color: var(--bg-hover); }
.btn-attach:disabled { opacity: 0.45; cursor: not-allowed; }

.upload-progress { display: flex; align-items: center; gap: 0.75rem; padding: 0.5rem 1.25rem; background-color: var(--bg-tertiary); border-top: 1px solid var(--border-color); }
.upload-progress.hidden { display: none; }
.upload-progress-bar { flex: 1; height: 3px; background-color: var(--bg-hover); border-radius: 2px; overflow: hidden; position: relative; }
.upload-progress-bar::after { content: ''; position: absolute; top: 0; left: 0; height: 100%; width: 30%; background-color: var(--accent-primary); animation: progress-animation 1s ease-in-out infinite; }
@keyframes progress-animation { 0% { left: -30%; } 100% { left: 100%; } }
.upload-progress-text { font-size: 0.78rem; color: var(--text-secondary); }

/* ── File / image content ────────────────────────────────── */
.file-content { display: flex; flex-direction: column; }

.img-wrap { display: inline-block; border-radius: 8px; overflow: hidden; }
.img-wrap.img-loading {
    min-width: 140px; min-height: 90px;
    background-color: var(--bg-tertiary); border: 1px solid var(--border-color);
    display: flex; align-items: center; justify-content: center;
}
.img-wrap.img-loading::after {
    content: ''; width: 22px; height: 22px;
    border: 2px solid var(--border-color); border-top-color: var(--accent-primary);
    border-radius: 50%; animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.message-image { display: block; max-width: 300px; max-height: 300px; border-radius: 8px; cursor: pointer; transition: opacity 0.2s; }
.message-image:hover { opacity: 0.85; }
.message-video { max-width: 300px; max-height: 300px; border-radius: 8px; }
.message-audio { width: 250px; }
.file-link {
    display: flex; align-items: center; gap: 0.75rem; padding: 0.6rem 0.75rem;
    background-color: var(--bg-tertiary); border: 1px solid var(--border-color);
    border-radius: 8px; color: var(--text-primary);
    cursor: pointer; font-family: inherit; text-align: left;
    transition: background-color 0.2s, border-color 0.2s; width: 100%;
}
.file-link:hover:not(:disabled) { background-color: var(--bg-hover); border-color: var(--accent-secondary); }
.file-link:disabled { opacity: 0.6; cursor: not-allowed; }
.file-link svg { flex-shrink: 0; color: var(--accent-primary); }
.file-info { display: flex; flex-direction: column; min-width: 0; flex: 1; }
.file-name { font-size: 0.85rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.file-size { font-size: 0.72rem; color: var(--text-muted); }

.message-form textarea {
    flex: 1; padding: 0.75rem 1rem; font-size: 0.9rem; font-family: inherit;
    background-color: var(--bg-tertiary); border: 1px solid var(--border-color);
    border-radius: 8px; color: var(--text-primary); resize: none;
    min-height: 44px; max-height: 150px;
    transition: background-color 0.3s, border-color 0.2s, color 0.3s, box-shadow 0.2s;
}
.message-form textarea:focus {
    outline: none; border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(57,255,20,0.08);
}
[data-theme="light"] .message-form textarea:focus { box-shadow: 0 0 0 3px rgba(0,100,0,0.08); }
.message-form textarea:disabled { opacity: 0.45; }
.message-form button[type="submit"] {
    padding: 0.75rem 1.5rem; font-size: 0.85rem; font-weight: 700; font-family: inherit;
    background: var(--accent-primary);
    color: #041004; border: none; border-radius: 8px; cursor: pointer;
    transition: background-color 0.2s;
    text-transform: uppercase; letter-spacing: 0.06em;
}
[data-theme="light"] .message-form button[type="submit"] { background: var(--accent-primary); color: #fff; }
.message-form button[type="submit"]:hover:not(:disabled) {
    background: #4dff28;
}
.message-form button[type="submit"]:disabled { opacity: 0.45; cursor: not-allowed; }

.crypto-info { padding: 0.65rem 1.25rem; background-color: var(--bg-secondary); border-top: 1px solid var(--border-color); transition: background-color 0.3s; }
.crypto-info details { font-size: 0.78rem; }
.crypto-info summary { cursor: pointer; color: var(--text-secondary); user-select: none; }
.crypto-info summary:hover { color: var(--text-primary); }
.crypto-info p { margin-top: 0.5rem; color: var(--text-muted); font-size: 0.72rem; }

/* ── Toast & Modal ───────────────────────────────────────── */
.toast {
    position: fixed; bottom: 2rem; left: 50%; transform: translateX(-50%);
    background-color: var(--accent-success); color: #041004;
    padding: 0.7rem 1.5rem; border-radius: 8px; font-size: 0.85rem; font-weight: 600;
    opacity: 0; transition: opacity 0.3s; pointer-events: none; z-index: 1000;
    box-shadow: 0 4px 20px rgba(57,255,20,0.4);
}
[data-theme="light"] .toast { color: #fff; background: var(--accent-secondary); }
.toast.show { opacity: 1; }

.modal-overlay {
    position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    background-color: rgba(0, 0, 0, 0.85); backdrop-filter: blur(4px); -webkit-backdrop-filter: blur(4px);
    display: flex; align-items: center; justify-content: center;
    z-index: 2000; opacity: 0; transition: opacity 0.2s; padding: 1rem;
}
.modal-overlay.show { opacity: 1; }
.modal {
    background-color: var(--bg-secondary); border: 1px solid var(--border-color);
    border-radius: 12px; max-width: 400px; width: 100%;
    transform: scale(0.95); transition: transform 0.2s, background-color 0.3s;
    box-shadow: 0 24px 64px rgba(0,0,0,0.7);
}
.modal-overlay.show .modal { transform: scale(1); }
.modal-header { display: flex; align-items: center; gap: 0.75rem; padding: 1.25rem; border-bottom: 1px solid var(--border-color); }
.modal-icon { font-size: 1.5rem; display: flex; align-items: center; justify-content: center; color: var(--accent-warning); }
.modal-header h3 { margin: 0; font-size: 1rem; color: var(--accent-warning); font-weight: 700; }
.modal-body { padding: 1.25rem; }
.modal-filename { font-family: monospace; background-color: var(--bg-tertiary); padding: 0.5rem 0.75rem; border-radius: 6px; font-size: 0.83rem; margin-bottom: 1rem; word-break: break-all; color: var(--text-secondary); }
.modal-warnings { list-style: none; padding: 0; margin: 0; }
.modal-warnings li { position: relative; padding-left: 1.25rem; margin-bottom: 0.5rem; font-size: 0.84rem; color: var(--text-secondary); }
.modal-warnings li::before { content: "\2022"; position: absolute; left: 0; color: var(--accent-warning); }
.modal-warnings strong { color: var(--accent-warning); }
.modal-actions { display: flex; gap: 0.75rem; padding: 1.25rem; border-top: 1px solid var(--border-color); }
.modal-actions button { flex: 1; padding: 0.75rem; border-radius: 8px; }

.btn-danger {
    background-color: var(--accent-danger); color: #fff; border: none; cursor: pointer;
    font-family: inherit; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.05em; border-radius: 8px;
    transition: background-color 0.2s, opacity 0.2s, box-shadow 0.2s;
}
.btn-danger:hover:not(:disabled) { background-color: #ff5555; box-shadow: 0 4px 14px rgba(255,69,69,0.4); }
.btn-danger:disabled { opacity: 0.45; cursor: not-allowed; }
.btn-danger-small {
    background: none; border: 1px solid var(--border-color); border-radius: 6px;
    padding: 0.4rem; cursor: pointer; color: var(--text-muted);
    transition: color 0.2s, border-color 0.2s; display: flex; align-items: center; justify-content: center;
}
.btn-danger-small:hover { color: var(--accent-danger); border-color: var(--accent-danger); }
.chat-header-actions { display: flex; align-items: center; gap: 0.75rem; }

.modal-text { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 1rem; }
.modal-error { color: var(--accent-danger); font-size: 0.83rem; margin-top: 0.75rem; }
.modal-error.hidden { display: none; }
.modal .form-group { margin-bottom: 0; }
.modal .form-group input { margin-top: 0.5rem; }

/* ── Scrollbar ───────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--bg-hover); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--border-color); }

/* ── Responsive ──────────────────────────────────────────── */
@media (max-width: 700px) {
    header { padding: 1.25rem 1rem; }
    header h1 { font-size: 1.9rem; }
    .tagline { font-size: 0.78rem; }
    .header-left, .header-right { width: 50px; }
    main { padding: 1.25rem 1rem; }
    .landing-content { gap: 2rem; }
    .features { grid-template-columns: 1fr; gap: 0; }
    .transparency ul { grid-template-columns: 1fr; }
    .actions { gap: 0.6rem; max-width: 100%; }
    .btn-primary, .btn-secondary { padding: 0.75rem 1.25rem; font-size: 0.9rem; }
    .form-group input { padding: 0.85rem; }
    .input-with-action { flex-wrap: wrap; gap: 0.5rem; }
    .input-with-action input { flex: 1 1 100%; }
    .input-with-action button { flex: 1; }
    .chat-header { flex-wrap: wrap; gap: 0.5rem; padding: 0.75rem 1rem; }
    .btn-back { position: static; transform: none; padding: 0.5rem 0.75rem; font-size: 0.9rem; }
    .chat-info { order: 3; width: 100%; justify-content: center; }
    .message { max-width: 88%; }
    .alias-bar { flex-direction: column; align-items: stretch; gap: 0.5rem; padding: 0.75rem 1rem; }
    .alias-bar input { max-width: 100%; }
    .message-form { padding: 0.75rem; gap: 0.5rem; }
    .message-form textarea { font-size: 1rem; padding: 0.75rem; min-height: 48px; }
    .message-form button[type="submit"] { padding: 0.75rem 1rem; font-size: 0.82rem; }
    .scroll-to-bottom { bottom: 0.5rem; right: 0.75rem; }
    footer { padding: 1rem; }
}

@media (max-width: 480px) {
    header h1 { font-size: 1.5rem; letter-spacing: 0.1em; }
    main { padding: 1rem 0.75rem; }
    .message-form { flex-direction: column; }
    .message-form button[type="submit"] { width: 100%; }
}