* { box-sizing: border-box; }
:root {
    --bg: #eef6ff;
    --bg-soft: #f8fbff;
    --text: #16324f;
    --muted: #5a728e;
    --line: rgba(140, 174, 205, 0.32);
    --primary: #1d9bf0;
    --primary-dark: #0f6fcc;
    --accent: #0fd4c2;
    --white: #ffffff;
    --shadow: 0 25px 60px rgba(30, 80, 120, 0.16);
}
html { scroll-behavior: smooth; }
body {
    margin: 0;
    min-height: 100vh;
    font-family: 'Inter', Arial, sans-serif;
    color: var(--text);
    background:
        radial-gradient(circle at top left, rgba(15, 212, 194, 0.16), transparent 28%),
        radial-gradient(circle at bottom right, rgba(29, 155, 240, 0.18), transparent 24%),
        linear-gradient(135deg, var(--bg) 0%, var(--bg-soft) 48%, #ffffff 100%);
}
a { color: inherit; text-decoration: none; }
button, input { font: inherit; }
.glass {
    background: rgba(255, 255, 255, 0.76);
    backdrop-filter: blur(18px);
    border: 1px solid rgba(255, 255, 255, 0.64);
    box-shadow: var(--shadow);
}
.hero-badge, .pill {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    border-radius: 999px;
    padding: 10px 16px;
    background: rgba(29, 155, 240, 0.12);
    color: var(--primary-dark);
    font-weight: 700;
    font-size: 14px;
}
.button {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
    padding: 14px 22px;
    border-radius: 18px;
    border: none;
    cursor: pointer;
    transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
    box-shadow: 0 12px 26px rgba(29, 155, 240, 0.18);
}
.button:hover { transform: translateY(-2px); }
.button.primary {
    color: var(--white);
    background: linear-gradient(135deg, var(--primary), var(--accent));
}
.button.secondary {
    color: var(--primary-dark);
    background: rgba(255, 255, 255, 0.95);
    border: 1px solid rgba(29, 155, 240, 0.16);
    box-shadow: none;
}
.ghost-link {
    color: var(--primary-dark);
    font-weight: 600;
}
.hero-title, h1, h2, h3 { letter-spacing: -0.04em; }
.hero-title { font-size: clamp(2.6rem, 6vw, 4.6rem); line-height: .95; margin: 18px 0; }
.hero-copy, .auth-copy, p, small { color: var(--muted); line-height: 1.7; }
.landing-shell, .auth-shell {
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding: 32px;
}
.hero-card {
    width: min(1180px, 100%);
    border-radius: 36px;
    padding: 36px;
    background: rgba(255,255,255,0.82);
    box-shadow: var(--shadow);
    border: 1px solid rgba(255,255,255,0.75);
}
.hero-grid {
    display: grid;
    grid-template-columns: 1.15fr .85fr;
    gap: 28px;
    align-items: center;
}
.hero-actions, .button-row {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: 24px;
}
.hero-list {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    list-style: none;
    padding: 0;
    margin: 26px 0 0;
}
.hero-list li {
    background: rgba(255,255,255,0.88);
    border: 1px solid var(--line);
    border-radius: 18px;
    padding: 12px 16px;
    font-weight: 600;
}
.preview-card {
    display: flex;
    justify-content: center;
}
.preview-window {
    width: min(420px, 100%);
    padding: 20px;
    border-radius: 30px;
    background: linear-gradient(180deg, #fdfefe 0%, #edf7ff 100%);
    border: 1px solid rgba(29, 155, 240, 0.16);
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.85), 0 35px 50px rgba(35, 97, 148, 0.18);
}
.preview-topbar { display: flex; gap: 8px; margin-bottom: 18px; }
.preview-topbar span {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: rgba(22, 50, 79, 0.18);
}
.preview-chat {
    padding: 18px;
    border-radius: 24px;
    background: rgba(255,255,255,0.88);
    border: 1px solid rgba(29, 155, 240, 0.14);
}
.preview-bubble {
    max-width: 78%;
    padding: 14px 16px;
    border-radius: 18px;
    margin-bottom: 12px;
    font-weight: 500;
}
.preview-bubble.incoming {
    background: #f3f7fb;
    color: var(--text);
}
.preview-bubble.outgoing {
    margin-left: auto;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
}
.preview-users { display: flex; gap: 10px; margin-top: 16px; }
.mini-user, .avatar {
    display: inline-grid;
    place-items: center;
    border-radius: 50%;
    color: white;
    font-weight: 800;
}
.mini-user {
    width: 42px;
    height: 42px;
    background: rgba(29, 155, 240, 0.72);
}
.mini-user.active { background: linear-gradient(135deg, var(--primary), var(--accent)); }
.auth-panel {
    width: min(520px, 100%);
    padding: 34px;
    border-radius: 28px;
}
.auth-panel.wide { width: min(720px, 100%); }
.stack-form {
    display: grid;
    gap: 16px;
    margin-top: 24px;
}
.stack-form.two-col {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}
.stack-form label {
    display: grid;
    gap: 8px;
    font-weight: 600;
}
.stack-form label span { font-size: 14px; }
.stack-form input {
    width: 100%;
    padding: 14px 16px;
    border-radius: 16px;
    border: 1px solid rgba(29, 155, 240, 0.14);
    background: rgba(255,255,255,0.92);
    outline: none;
}
.stack-form input:focus {
    border-color: rgba(29, 155, 240, 0.52);
    box-shadow: 0 0 0 4px rgba(29, 155, 240, 0.12);
}
.auth-links {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    margin-top: 18px;
    font-weight: 600;
    color: var(--primary-dark);
}
.auth-links.left { justify-content: flex-start; }
.alert {
    border-radius: 18px;
    padding: 14px 16px;
    margin-top: 18px;
    font-weight: 600;
}
.alert.error {
    color: #a33434;
    background: rgba(255, 92, 92, 0.12);
    border: 1px solid rgba(255, 92, 92, 0.2);
}
.alert.success {
    color: #0b7a61;
    background: rgba(13, 217, 168, 0.12);
    border: 1px solid rgba(13, 217, 168, 0.22);
}
.debug-note, .token-box {
    margin-top: 18px;
    padding: 14px 16px;
    border-radius: 18px;
    background: rgba(22, 50, 79, 0.06);
    color: var(--muted);
    overflow-wrap: anywhere;
}
.dashboard-shell {
    min-height: 100vh;
    display: grid;
    grid-template-columns: 340px minmax(0, 1fr);
    gap: 22px;
    padding: 22px;
}
.sidebar, .content-panel {
    border-radius: 28px;
    padding: 24px;
}
.sidebar-top, .content-head {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    align-items: center;
}
.profile-card {
    display: grid;
    grid-template-columns: 76px 1fr;
    gap: 16px;
    align-items: center;
    padding: 22px 0;
}
.avatar {
    width: 72px;
    height: 72px;
    font-size: 24px;
}
.avatar.large {
    width: 64px;
    height: 64px;
    font-size: 20px;
    margin: 0 auto 12px;
}
.profile-card h1, .user-card h3, .empty-card h3 { margin: 0 0 6px; }
.profile-card p, .user-card p { margin: 0 0 4px; }
.panel-note {
    border-top: 1px solid var(--line);
    padding-top: 20px;
    color: var(--muted);
    line-height: 1.7;
}
.section-kicker {
    font-weight: 700;
    color: var(--primary-dark);
    text-transform: uppercase;
    letter-spacing: .08em;
    font-size: 12px;
}
.content-head h2 { margin: 8px 0 0; font-size: clamp(2rem, 3vw, 2.8rem); }
.user-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 18px;
    margin-top: 24px;
}
.user-card, .empty-card {
    border-radius: 24px;
    padding: 22px;
    background: rgba(255,255,255,0.88);
    border: 1px solid var(--line);
    text-align: center;
}
.empty-card {
    text-align: left;
    grid-column: 1 / -1;
}
@media (max-width: 980px) {
    .hero-grid,
    .dashboard-shell,
    .stack-form.two-col {
        grid-template-columns: 1fr;
    }
    .dashboard-shell { padding: 16px; }
}
@media (max-width: 640px) {
    .landing-shell, .auth-shell { padding: 18px; }
    .hero-card, .auth-panel, .sidebar, .content-panel { padding: 22px; border-radius: 24px; }
    .hero-title { font-size: 2.4rem; }
    .auth-links, .sidebar-top, .content-head { flex-direction: column; align-items: flex-start; }
}
