@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
    --bg: #0b0b0d;
    --panel: #121216;
    --panel-soft: #17171c;
    --line: rgba(255, 255, 255, 0.08);
    --text: #f5f5f7;
    --muted: #9a9aa3;
    --accent: #ffffff;
    --shadow: 0 24px 80px rgba(0, 0, 0, 0.32);
    --radius: 24px;
    --radius-sm: 18px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    background:
        radial-gradient(circle at top, rgba(255, 255, 255, 0.05), transparent 30%),
        linear-gradient(180deg, #0a0a0c 0%, #0f1013 100%);
    color: var(--text);
    font-family: 'Inter', 'Segoe UI', sans-serif;
}

button,
textarea {
    font: inherit;
}

button {
    cursor: pointer;
}

.app-shell {
    width: min(100%, 960px);
    margin: 0 auto;
    padding: 40px 18px 72px;
}

.hero {
    min-height: 72vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.brand {
    margin: 0 0 14px;
    color: var(--muted);
    letter-spacing: 0.22em;
    text-transform: uppercase;
    font-size: 0.78rem;
}

.brand-small {
    margin-bottom: 8px;
}

.hero h1,
.response-toolbar h2,
.response-section h3 {
    margin: 0;
    font-weight: 600;
    letter-spacing: -0.04em;
}

.hero h1 {
    font-size: clamp(2.6rem, 7vw, 4.8rem);
}

.tagline {
    margin: 16px 0 28px;
    max-width: 620px;
    color: var(--muted);
    font-size: 1.02rem;
    line-height: 1.7;
}

.prompt-form {
    width: min(100%, 780px);
}

.prompt-bar {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 12px;
    align-items: end;
    padding: 12px;
    border-radius: 28px;
    background: rgba(18, 18, 22, 0.94);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

#prompt {
    width: 100%;
    min-height: 58px;
    max-height: 220px;
    border: 0;
    outline: none;
    resize: none;
    background: transparent;
    color: var(--text);
    padding: 10px 12px;
    line-height: 1.6;
}

#prompt::placeholder {
    color: #7f8088;
}

.send-button,
.ghost-button {
    border: 1px solid var(--line);
    border-radius: 999px;
    padding: 12px 18px;
    background: var(--accent);
    color: #0b0b0d;
    transition: opacity 0.2s ease, transform 0.2s ease, background 0.2s ease;
}

.ghost-button {
    background: transparent;
    color: var(--text);
}

.send-button:hover,
.ghost-button:hover {
    transform: translateY(-1px);
}

.send-button:disabled,
.ghost-button:disabled {
    opacity: 0.45;
    cursor: not-allowed;
    transform: none;
}

.microcopy {
    margin: 16px 0 0;
    min-height: 24px;
    color: var(--muted);
    font-size: 0.92rem;
}

.response-shell {
    display: grid;
    gap: 18px;
}

.response-toolbar,
.message-card {
    padding: 22px;
    border-radius: var(--radius);
    background: rgba(18, 18, 22, 0.94);
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.response-toolbar {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    align-items: flex-start;
}

.toolbar-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.message-card {
    line-height: 1.8;
}

.answer-card {
    background: rgba(20, 20, 25, 0.96);
}

.message-label {
    margin-bottom: 12px;
    color: var(--muted);
    text-transform: uppercase;
    letter-spacing: 0.18em;
    font-size: 0.74rem;
}

.message-text,
.response-paragraph,
.inline-heading {
    margin: 0;
    color: var(--text);
}

.response-blocks {
    display: grid;
    gap: 26px;
}

.response-section {
    display: grid;
    gap: 14px;
}

.response-section h3 {
    font-size: 1.05rem;
}

.response-paragraph {
    color: #e6e6ea;
}

.inline-heading {
    font-weight: 600;
}

.response-list {
    margin: 0;
    padding-left: 20px;
    display: grid;
    gap: 10px;
    color: #e6e6ea;
}

.hidden {
    display: none;
}

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

@media (max-width: 720px) {
    .app-shell {
        padding-top: 24px;
    }

    .hero {
        min-height: 60vh;
    }

    .prompt-bar {
        grid-template-columns: 1fr;
        border-radius: 24px;
    }

    .response-toolbar {
        flex-direction: column;
    }

    .toolbar-actions {
        width: 100%;
    }

    .ghost-button,
    .send-button {
        width: 100%;
    }
}