:root {
    --bg-color: #f4f4f9;
    --chat-bg: #ffffff;
    --text-color: #333333;
    --input-bg: #ffffff;
    --border-color: #e0e0e0;
    --user-msg-bg: #007bff;
    --user-msg-text: #ffffff;
    --ai-msg-bg: #f0f0f0;
    --ai-msg-text: #333333;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --glass-bg: rgba(255, 255, 255, 0.45);
    --glass-border: rgba(255, 255, 255, 0.35);
    --glass-shadow: 0 8px 32px rgba(31, 38, 135, 0.15);
    --code-bg: #f6f8fa;
    --code-fg: #24292e;
}

[data-theme="dark"] {
    --bg-color: #0a0a0a;
    --chat-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --input-bg: #2c2c2c;
    --border-color: #444444;
    --user-msg-bg: #3700b3;
    --user-msg-text: #ffffff;
    --ai-msg-bg: #333333;
    --ai-msg-text: #e0e0e0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.5);
    --glass-bg: rgba(30, 30, 30, 0.65);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --code-bg: #0d1117;
    --code-fg: #c9d1d9;
}

.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
}

.glass-subtle {
    background: var(--glass-bg);
    backdrop-filter: blur(12px) saturate(150%);
    -webkit-backdrop-filter: blur(12px) saturate(150%);
    border: 1px solid var(--glass-border);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family:
        -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
        Helvetica, Arial, sans-serif;
}

body {
    background: var(--bg-color);
    background-image:
        radial-gradient(
            ellipse at 20% 50%,
            rgba(59, 0, 179, 0.15) 0%,
            transparent 50%
        ),
        radial-gradient(
            ellipse at 80% 20%,
            rgba(0, 123, 255, 0.12) 0%,
            transparent 50%
        ),
        radial-gradient(
            ellipse at 50% 80%,
            rgba(100, 50, 200, 0.1) 0%,
            transparent 50%
        );
    color: var(--text-color);
    height: 100vh; /* fallback for older browsers */
    height: 100dvh; /* dynamic viewport: tracks mobile URL-bar show/hide */
    display: flex;
    justify-content: center;
    align-items: center;
    transition:
        background 0.3s,
        color 0.3s;
    overflow: hidden;
}

[data-theme="dark"] body {
    background: var(--bg-color);
    background-image:
        radial-gradient(
            ellipse at 20% 50%,
            rgba(55, 0, 179, 0.25) 0%,
            transparent 50%
        ),
        radial-gradient(
            ellipse at 80% 20%,
            rgba(59, 0, 179, 0.2) 0%,
            transparent 50%
        ),
        radial-gradient(
            ellipse at 50% 80%,
            rgba(100, 0, 210, 0.15) 0%,
            transparent 50%
        );
}

.container {
    width: 100%;
    max-width: 900px;
    height: 90vh; /* fallback */
    height: 90dvh;
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
}

header {
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 10px;
    z-index: 10;
}

h1 {
    flex: 1;
    min-width: 0;
    font-size: 1.2rem;
    font-weight: 600;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.theme-toggle {
    background: var(--glass-bg);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    border: 1px solid var(--glass-border);
    color: var(--text-color);
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

.theme-toggle:hover {
    background: var(--glass-border);
}

#chat-box {
    flex: 1;
    padding: 20px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 15px;
    scroll-behavior: smooth;
    background: transparent;
}

.message {
    max-width: 80%;
    padding: 12px 16px;
    border-radius: 12px;
    line-height: 1.5;
    font-size: 0.95rem;
    word-wrap: break-word;
    animation: fadeIn 0.3s ease;
    white-space: pre-wrap; /* Preserve whitespace for code blocks */
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.user-message {
    align-self: flex-end;
    background-color: var(--user-msg-bg);
    color: var(--user-msg-text);
    border-bottom-right-radius: 2px;
}

.ai-message {
    align-self: flex-start;
    width: fit-content;
    max-width: 80%;
    background: var(--ai-msg-bg);
    backdrop-filter: blur(8px) saturate(150%);
    -webkit-backdrop-filter: blur(8px) saturate(150%);
    border: 1px solid var(--glass-border);
    color: var(--ai-msg-text);
    border-bottom-left-radius: 2px;
}

/* Inner content that is intrinsically wide (tables, display math)
   expands the bubble to the full chat width; anything still wider
   scrolls horizontally inside the bubble. */
.ai-message:has(table, .katex-display) {
    max-width: 100%;
}

.ai-message img {
    max-width: 100%;
    height: auto;
}

#chat-box li p {
    display: inline !important;
}

.message ul,
.message ol {
    margin: 0 0 !important;
    padding-left: 1.4em !important;
}

.message thinking ul,
.message thinking ol {
    margin: -3em 0 0 0 !important;
}

.message ul ul,
.message ol ol,
.message ul ol,
.message ol ul {
    margin: 0 !important;
}

.message li {
    text-align: left;
}

.table-scroll {
    overflow-x: auto;
    max-width: 100%;
}

.ai-message table {
    border-collapse: collapse;
    width: 100%;
    margin: 0.5em 0;
    font-size: 0.9rem;
}

.ai-message th,
.ai-message td {
    border: 1px solid var(--glass-border);
    padding: 8px 12px;
    text-align: left;
}

.ai-message th {
    background: rgba(128, 128, 128, 0.15);
    font-weight: 600;
}

.ai-message tr:nth-child(even) td {
    background: rgba(128, 128, 128, 0.05);
}

.message pre {
    position: relative;
    margin: 0.5em 0;
    padding: 12px;
    border-radius: 8px;
    overflow-x: auto;
    font-size: 0.85em;
    line-height: 1.6;
    background: var(--code-bg);
    color: var(--code-fg);
    font-family:
        "SF Mono", "Fira Code", "Fira Mono", Menlo, Consolas,
        "Liberation Mono", Courier, monospace;
}

.message code {
    font-family:
        "SF Mono", "Fira Code", "Fira Mono", Menlo, Consolas,
        "Liberation Mono", Courier, monospace !important;
    background: rgba(128, 128, 128, 0.12) !important;
    border-radius: 3px !important;
    padding: 2px 5px !important;
    font-size: 0.9em !important;
}

.message code span {
    font-family: inherit !important;
}

.message pre code {
    background: none !important;
    border-radius: 0 !important;
    padding: 0 !important;
}

.code-header-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 4px 12px;
    margin: 0;
    background: rgba(128, 128, 128, 0.15) !important;
    border-radius: 8px 8px 0 0;
    font-size: 0.75rem;
    font-family: sans-serif;
}

.code-header-bar + pre {
    margin-top: 0 !important;
    border-radius: 0 0 8px 8px;
}

.copy-btn {
    background: none;
    border: 1px solid var(--glass-border);
    color: var(--text-color);
    padding: 2px 8px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.75rem;
    opacity: 0.7;
    transition: all 0.15s;
}

.copy-btn:hover {
    opacity: 1;
    background: rgba(128, 128, 128, 0.1);
}

.input-area {
    padding: 20px;
    border-top: 1px solid var(--glass-border);
    background: var(--glass-bg);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    display: flex;
    gap: 10px;
}

textarea {
    flex: 1;
    padding: 12px;
    border-radius: 8px;
    border: 1px solid var(--glass-border);
    background: var(--glass-bg);
    backdrop-filter: blur(8px) saturate(150%);
    -webkit-backdrop-filter: blur(8px) saturate(150%);
    color: var(--text-color);
    resize: none;
    height: 50px;
    outline: none;
    font-size: 0.95rem;
    transition:
        border-color 0.2s,
        box-shadow 0.2s;
}

textarea:focus {
    border-color: var(--user-msg-bg);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.2);
}

button#send-btn {
    padding: 0 20px;
    background: var(--user-msg-bg);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    transition:
        opacity 0.2s,
        transform 0.1s;
}

button#send-btn:hover {
    opacity: 0.9;
    transform: scale(1.02);
}
button#send-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

textarea:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.speech-btn {
    min-width: 50px;
    padding: 0 14px;
    background: var(--glass-bg);
    color: var(--text-color);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition:
        opacity 0.2s,
        transform 0.1s,
        background 0.2s,
        box-shadow 0.2s;
}

.speech-btn:hover {
    background: rgba(128, 128, 128, 0.1);
}

.speech-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.speech-btn.listening {
    background: rgba(220, 53, 69, 0.15);
    border-color: rgba(220, 53, 69, 0.6);
    color: #dc3545;
    animation: micPulse 1.2s ease-in-out infinite;
}

@keyframes micPulse {
    0%,
    100% {
        box-shadow: 0 0 0 0 rgba(220, 53, 69, 0.35);
    }
    50% {
        box-shadow: 0 0 0 6px rgba(220, 53, 69, 0);
    }
}

.speaker-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 26px;
    height: 26px;
    padding: 0;
    margin-left: 6px;
    vertical-align: middle;
    transform: translateY(-1px);
    background: transparent;
    color: var(--text-muted, var(--text-color, inherit));
    border: none;
    border-radius: 6px;
    cursor: pointer;
    opacity: 0.6;
    transition:
        opacity 0.2s,
        background 0.2s;
}

.speaker-btn:hover {
    opacity: 1;
    background: rgba(128, 128, 128, 0.12);
}

.speaker-btn.speaking {
    opacity: 1;
    color: #007bff;
    animation: speakPulse 1s ease-in-out infinite;
}

@keyframes speakPulse {
    0%,
    100% {
        opacity: 1;
    }
    50% {
        opacity: 0.4;
    }
}

.followup-speaker {
    width: 20px;
    height: 20px;
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: #888;
}

thinking {
    font-size: 0.8em;
    font-style: italic;
}

answer {
    display: block;
    clear: both;
}

/* Links in AI response content */
.ai-message a {
    color: var(--user-msg-bg);
    text-decoration: underline;
}

.ai-message a:hover {
    opacity: 0.85;
    background: rgba(55, 133, 255, 0.1);
    padding: 2px 4px;
    border-radius: 2px;
}

/* Dark mode links in AI response - yellow for visibility */
[data-theme="dark"] .ai-message a {
    color: #ffc107 !important;
}

.settings-modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    animation: fadeIn 0.2s ease;
}

.settings-modal {
    width: 500px;
    max-width: 90%;
    border-radius: 12px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    background: var(--chat-bg);
    position: relative;
}

.modal-close-btn {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: none;
    border-radius: 8px;
    color: var(--text-color);
    font-size: 1.4rem;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.15s ease, background 0.15s ease;
}

.modal-close-btn:hover {
    opacity: 1;
    background: var(--glass-bg);
}

.settings-modal h2 {
    font-size: 1.1rem;
    font-weight: 600;
}

.settings-modal label {
    font-size: 0.9rem;
    font-weight: 500;
}

.settings-modal textarea {
    height: 120px;
    resize: vertical;
}

.settings-modal .btn-row {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

.shortcuts-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.shortcut {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
}

.shortcut kbd {
    font-family: inherit;
    font-size: 0.75rem;
    padding: 2px 6px;
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    min-width: 36px;
    text-align: center;
}

.shortcut span {
    flex: 1;
    font-size: 0.85rem;
    color: var(--text-color);
    opacity: 0.8;
}

.settings-modal .btn-row button {
    padding: 8px 16px;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
}

.shortcuts-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin: 8px 0;
}

.shortcut {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 12px;
    background: var(--glass-bg);
    border-radius: 8px;
    border: 1px solid var(--glass-border);
}

.shortcut kbd {
    background: var(--glass-border);
    padding: 3px 8px;
    border-radius: 5px;
    font-family: monospace;
    font-size: 0.85rem;
    font-weight: 500;
    white-space: nowrap;
}

.shortcut span {
    flex: 1;
    font-size: 0.9rem;
    color: var(--text-color);
    opacity: 0.85;
}

.settings-modal .btn-save {
    background: var(--user-msg-bg);
    color: white;
}

.settings-modal .btn-cancel {
    background: var(--ai-msg-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.settings-btn {
    background: var(--glass-bg);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    border: 1px solid var(--glass-border);
    color: var(--text-color);
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s;
}

.settings-btn:hover {
    background: var(--glass-border);
}

.settings-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.disclaimer {
    padding: 8px 20px;
    font-size: 0.78rem;
    font-style: italic;
    color: var(--text-color);
    opacity: 0.6;
    text-align: center;
    border-top: 1px solid var(--glass-border);
}
/* Hidden utility class */
.hidden {
    display: none !important;
}

.loader {
    display: flex;
    gap: 6px;
    align-items: center;
}

.loader span {
    width: 6px;
    height: 6px;
    background-color: #aaa;
    border-radius: 50%;
    animation: bounce 0.6s infinite alternate;
}

.loader span:nth-child(2) {
    animation-delay: 0.2s;
}

.loader span:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes bounce {
    to {
        transform: translateY(-4px);
        opacity: 0.4;
    }
}

#loading-overlay {
    position: fixed;
    inset: 0;
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--bg-color);
    transition: opacity 0.3s;
}

#loading-overlay.loading-overlay-hidden {
    opacity: 0;
    pointer-events: none;
}

.followup-container {
    margin-top: 8px;
    padding-left: 12px;
}

.followup-link {
    display: block;
    margin: 4px 0;
    color: var(--user-msg-bg);
    text-decoration: none;
    font-size: 0.9rem;
    cursor: pointer;
    padding: 6px 10px;
    border-radius: 6px;
    background: rgba(55, 133, 255, 0.1);
    transition: background 0.2s, color 0.2s;
}

.followup-link:hover {
    background: rgba(55, 133, 255, 0.2);
}

[data-theme="dark"] .followup-link {
    color: #ffc107 !important;
}

[data-theme="dark"] .followup-link:hover {
    background: rgba(255, 193, 7, 0.25);
}

/* Inner cards stay visible on the bright modal surface */
.settings-modal .shortcut {
    background: var(--bg-color);
    border-color: var(--border-color);
}

.settings-modal .history-row:not(.history-row-active) {
    background: var(--bg-color);
    border-color: var(--border-color);
}

/* Language switcher modal */
.lang-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.lang-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 12px;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.92rem;
    transition:
        background 0.15s,
        border-color 0.15s;
}

.lang-row:hover {
    background: rgba(55, 133, 255, 0.08);
    border-color: var(--glass-border);
}

.lang-row-active {
    border-color: var(--user-msg-bg);
}

.lang-row .lang-native {
    font-weight: 600;
}

.lang-row .lang-en {
    opacity: 0.6;
    font-size: 0.8rem;
}

.lang-row .lang-check {
    margin-left: auto;
    color: var(--user-msg-bg);
    font-weight: 700;
}

/* Chat history modal */
.history-modal {
    width: 560px;
}

.history-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 12px;
}

.history-header .btn-save {
    padding: 8px 16px;
    border-radius: 8px;
    border: none;
    cursor: pointer;
}

.history-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    max-height: 320px;
    overflow-y: auto;
    margin: 8px 0;
}

.history-row {
    position: relative;
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: 10px 12px;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    cursor: pointer;
    transition:
        background 0.15s,
        border-color 0.15s;
}

.history-row:hover {
    background: rgba(55, 133, 255, 0.08);
}

.history-row-active {
    border-color: var(--user-msg-bg);
}

.history-row-disabled,
.history-row-disabled:hover {
    opacity: 0.5;
    cursor: default;
    background: var(--glass-bg);
}

.history-subject {
    font-size: 0.9rem;
    font-weight: 600;
    padding-right: 28px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.history-meta {
    font-size: 0.75rem;
    opacity: 0.6;
}

.history-delete {
    position: absolute;
    top: 8px;
    right: 8px;
    background: none;
    border: none;
    color: var(--text-color);
    opacity: 0.5;
    cursor: pointer;
    font-size: 0.85rem;
    padding: 4px 6px;
    border-radius: 4px;
}

.history-delete:hover {
    opacity: 1;
    background: rgba(255, 80, 80, 0.15);
}

.history-delete:disabled {
    opacity: 0.3;
    cursor: default;
}

.history-empty {
    padding: 24px;
    text-align: center;
    opacity: 0.6;
    font-size: 0.9rem;
}

/* ==================================================================
   Header button layout & kebab dropdown
   ================================================================== */

.header-buttons {
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-always-visible {
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-kebab-wrapper {
    position: relative;
}

.header-kebab-dropdown {
    display: none;
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    min-width: 160px;
    background: var(--chat-bg);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    box-shadow: var(--glass-shadow);
    z-index: 200;
    overflow: hidden;
    flex-direction: column;
    gap: 0;
}

.header-kebab-dropdown.kebab-open {
    display: flex;
}

.kebab-item {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
    padding: 10px 14px;
    background: none;
    border: none;
    color: var(--text-color);
    font-size: 0.88rem;
    cursor: pointer;
    text-align: left;
    transition: background 0.15s;
}

.kebab-item:hover {
    background: rgba(128, 128, 128, 0.12);
}

.kebab-item:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.kebab-item:disabled:hover {
    background: none;
}

.kebab-icon {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    width: 20px;
    justify-content: center;
}

.kebab-label {
    flex: 1;
}

/* --- Responsive visibility --- */

/* Mobile (<=768px): kebab visible, PDF/theme/lang hidden */
@media (max-width: 768px) {
    .header-kebab-wrapper {
        display: block;
    }

    .header-pdf-btn,
    .header-theme-btn,
    .header-lang-btn {
        display: none !important;
    }
}

/* Tablet portrait (769-1024px, portrait): kebab visible, PDF inline, theme/lang hidden */
@media (min-width: 769px) and (max-width: 1024px) and (orientation: portrait) {
    .header-kebab-wrapper {
        display: block;
    }

    .header-pdf-btn {
        display: flex;
    }

    .header-theme-btn,
    .header-lang-btn {
        display: none !important;
    }

    #dropdown-pdf-btn {
        display: none !important;
    }
}

/* Tablet landscape+ and desktop: kebab hidden, all buttons visible */
@media (min-width: 1025px), (orientation: landscape) and (min-width: 769px) {
    .header-kebab-wrapper {
        display: none !important;
    }

    .header-pdf-btn,
    .header-theme-btn,
    .header-lang-btn {
        display: flex;
    }
}

/* ==================================================================
   Responsive: mobile, tablet, laptop, desktop & TV
   ================================================================== */

html {
    -webkit-text-size-adjust: 100%;
}

/* Touch ergonomics & prevent double-tap zoom lag on mobile */
button,
a,
.followup-link,
.settings-btn,
.kebab-item,
#send-btn {
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

body {
    overflow-x: hidden;
    overscroll-behavior-y: contain;
}

/* ---------- Phones & small tablets (portrait) ---------- */
@media (max-width: 768px) {
    .container {
        max-width: none;
        height: 100vh;
        height: 100dvh;
        border-radius: 0;
        border: none;
        box-shadow: none;
    }

    header {
        padding: 12px;
        padding-top: calc(12px + env(safe-area-inset-top, 0px));
    }

    #chat-box {
        padding: 14px 12px;
        gap: 12px;
    }

    .message {
        max-width: 95%;
        font-size: 0.92rem;
        padding: 10px 12px;
    }

    /* 16px+ prevents iOS auto-zoom when focusing the input */
    textarea {
        font-size: 16px;
    }

    .input-area {
        padding: 10px 12px;
        padding-bottom: calc(10px + env(safe-area-inset-bottom, 0px));
    }

    button#send-btn {
        min-width: 72px;
        min-height: 44px;
        padding: 0 16px;
        font-size: 0.95rem;
    }

    .speech-btn {
        min-width: 44px;
        min-height: 44px;
        padding: 0 10px;
    }

    .speaker-btn {
        width: 32px;
        height: 32px;
        opacity: 0.9;
    }

    .theme-toggle,
    .settings-btn {
        min-height: 40px;
        padding: 8px 10px;
        font-size: 0.85rem;
    }

    .followup-link {
        padding: 10px 12px;
    }

    .copy-btn {
        padding: 5px 10px;
    }

    /* Modal: full screen on phones */
    .settings-modal-overlay {
        align-items: stretch;
    }

    .settings-modal {
        width: 100%;
        max-width: 100%;
        min-height: 100vh;
        min-height: 100dvh;
        max-height: 100vh;
        max-height: 100dvh;
        overflow-y: auto;
        border-radius: 0;
        padding: 20px 16px;
        padding-top: calc(20px + env(safe-area-inset-top, 0px));
        padding-bottom: calc(20px + env(safe-area-inset-bottom, 0px));
    }
}

/* ---------- Very small phones ---------- */
@media (max-width: 400px) {
    header {
        padding-left: 10px;
        padding-right: 10px;
    }

    h1 {
        font-size: 1.02rem;
    }

    .message {
        max-width: 98%;
    }

    .theme-toggle {
        font-size: 0.8rem;
        padding: 8px;
    }

    .settings-btn {
        padding: 8px;
    }
}

/* ---------- Landscape phones / short viewports ---------- */
@media (orientation: landscape) and (max-height: 600px) {
    .container {
        height: 100vh;
        height: 100svh;
        height: 100dvh;
    }

    header {
        padding-top: calc(8px + env(safe-area-inset-top, 0px));
        padding-bottom: 8px;
    }

    #chat-box {
        padding: 10px 12px;
    }

    .input-area {
        padding: 8px 12px;
        padding-bottom: calc(8px + env(safe-area-inset-bottom, 0px));
    }

    .message {
        font-size: 0.9rem;
    }
}

/* ---------- Tablets (portrait & landscape) ---------- */
@media (min-width: 769px) and (max-width: 1024px) {
    .container {
        max-width: min(820px, calc(100% - 24px));
    }

    #chat-box {
        padding: 18px;
    }
}

/* ---------- Laptops & desktops (default styles apply) ---------- */

/* ---------- Large desktops / hi-DPI laptops ---------- */
@media (min-width: 1441px) and (max-width: 2560px) {
    html {
        font-size: 17px;
    }

    .container {
        max-width: 1100px;
    }
}

/* ---------- TVs / 4K and beyond ---------- */
@media (min-width: 2561px) {
    html {
        font-size: 22px;
    }

    .container {
        max-width: 1400px;
        height: 92vh;
        height: 92dvh;
    }

    header {
        padding: 20px 28px;
    }

    #chat-box {
        padding: 28px;
    }

    .input-area {
        padding: 24px 28px;
    }

    textarea {
        height: 56px;
    }

    .message {
        max-width: 85%;
    }
}