body {
    margin: 0;
    background: #0f172a;
    color: #e2e8f0;
    font: 16px/1.5 system-ui,Segoe UI,Roboto,Arial
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 16px
}

.log {
    height: 360px;
    overflow: auto;
    background: #0b1020;
    padding: 12px;
    border-radius: 10px
}

.row {
    display: flex;
    gap: 8px;
    margin-top: 8px
}

.input {
    flex: 1;
    padding: 10px;
    border-radius: 10px;
    border: 1px solid #24304a;
    background: #0b1020;
    color: #e2e8f0
}

.btn {
    padding: 10px 16px;
    border-radius: 10px;
    border: none;
    background: #22d3ee;
    color: #001018;
    font-weight: 700;
    cursor: pointer
}

.msg {
    margin: 8px 0;
    padding: 10px;
    border-radius: 10px;
    max-width: 80%
}

    .msg.user {
        background: #1f2937;
        align-self: flex-end
    }

    .msg.ai {
        background: #0a2530;
        border: 1px solid #133042
    }

/* ===== Layout + Theme ===== */
:root {
    --wrap: 1100px;
    --border: #1e2a44;
    --bg: #0b0f1a;
    --panel: #0f162c;
    --panel-2: #0d1324;
    --text: #e6eef7;
    --muted: #a7b4c8;
    --link: #9ecbff;
    --btn: #1f6feb;
    --btn-h: #2568d6;
}

* {
    box-sizing: border-box
}

html, body {
    height: 100%
}

body {
    font-family: system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
    background: var(--bg);
    color: var(--text);
    margin: 0;
}

a {
    color: inherit
}

.wrap {
    max-width: var(--wrap);
    margin: 0 auto;
    padding: 0 16px;
}

/* ===== Header / Nav ===== */
header {
    background: var(--panel-2);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 50;
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
    gap: 12px;
}

.brand a {
    color: var(--text);
    text-decoration: none;
    font-weight: 700;
    letter-spacing: .3px;
    white-space: nowrap;
}

/* Hamburger (CSS only) */
.nav-toggle {
    display: none;
}

.hamburger {
    display: none;
    width: 38px;
    height: 38px;
    padding: 8px;
    border-radius: 10px;
    border: 1px solid var(--border);
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

    .hamburger span {
        display: block;
        width: 100%;
        height: 2px;
        background: #c8d4e6;
        margin: 3px 0;
        transition: transform .2s ease, opacity .2s ease;
    }

/* menu container */
.menu {
    display: flex;
    gap: 14px;
    align-items: center;
}

    .menu a {
        color: #c8d4e6;
        text-decoration: none;
        padding: 6px 10px;
        border-radius: 8px;
    }

        .menu a:hover {
            background: #131b33;
            color: #fff;
        }

    .menu form {
        margin: 0;
    }

.btn {
    background: var(--btn);
    color: #fff;
    border: 0;
    padding: 8px 14px;
    border-radius: 10px;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
}

    .btn:hover {
        background: var(--btn-h);
    }

/* ===== Main/Footer ===== */
main {
    padding: 24px 0 48px;
}

.footer {
    padding: 24px 0;
    color: var(--muted);
    border-top: 1px solid var(--border);
    background: var(--panel-2);
}

/* ===== Utilities / Components ===== */
.card {
    background: var(--panel);
    border: 1px solid var(--border);
    border-radius: 14px;
    padding: 16px;
}

.row {
    display: flex;
    gap: 14px;
    flex-wrap: wrap;
}

    .row > * {
        flex: 1 1 260px;
        min-width: 0;
    }

.hero {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 24px;
    align-items: center;
}

    .hero h1 {
        margin: 0 0 10px;
        font-size: clamp(24px,4.5vw,38px);
        line-height: 1.15;
    }

    .hero p.lead {
        color: #c8d4e6;
        font-size: clamp(14px,1.8vw,18px);
    }

.pill {
    display: inline-block;
    background: #0c1b31;
    border: 1px solid var(--border);
    color: var(--link);
    padding: 6px 10px;
    border-radius: 999px;
    font-size: 13px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3,1fr);
    gap: 16px;
}

.feature h3 {
    margin: 8px 0;
    font-size: 18px;
}

.muted {
    color: var(--muted);
}

.cta {
    display: flex;
    gap: 10px;
    align-items: center;
    margin-top: 12px;
    flex-wrap: wrap;
}

a.link {
    color: var(--link);
    text-decoration: none;
}

    a.link:hover {
        text-decoration: underline;
    }

/* ===== Responsive ===== */
@media (max-width: 900px) {
    .nav {
        height: auto;
        padding: 8px 0;
    }

    .hamburger {
        display: flex;
    }

    .menu {
        display: none; /* collapsed by default */
        position: static;
        width: 100%;
        flex-direction: column;
        align-items: stretch;
        gap: 8px;
        padding: 12px 0 4px;
    }
    /* open when toggled */
    #nav-toggle:checked ~ .menu {
        display: flex;
    }

    /* animate hamburger to X when open */
    #nav-toggle:checked + label.hamburger span:nth-child(1) {
        transform: translateY(5px) rotate(45deg);
    }

    #nav-toggle:checked + label.hamburger span:nth-child(2) {
        opacity: 0;
    }

    #nav-toggle:checked + label.hamburger span:nth-child(3) {
        transform: translateY(-5px) rotate(-45deg);
    }

    .menu a, .menu .btn {
        width: 100%;
        text-align: center;
    }

    .menu form .btn {
        width: 100%;
    }

    .hero {
        grid-template-columns: 1fr;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }
}
/* ===== Auth (Login/Register) ===== */
.auth-wrap {
    min-height: calc(100vh - 120px); /* header+footer approx */
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px 16px;
}

.auth-card {
    width: 100%;
    max-width: 420px;
}

.auth-title {
    margin: 0 0 12px;
    text-align: center;
}

.auth-form {
    display: grid;
    gap: 12px;
}

.form-field {
    display: grid;
    gap: 6px;
}

    .form-field label {
        color: #c8d4e6;
        font-size: 14px;
    }

    .form-field input {
        width: 100%;
        padding: 10px 12px;
        border-radius: 10px;
        border: 1px solid var(--border);
        background: #0b1226;
        color: var(--text);
    }

        .form-field input:focus {
            outline: 2px solid #1f6feb33;
            border-color: #1f6feb;
        }

.w-full {
    width: 100%;
}

.alert {
    background: #0c1b31;
    border: 1px solid var(--border);
    color: #e6eef7;
    padding: 10px 12px;
    border-radius: 10px;
    margin-bottom: 12px;
}

    .alert.error {
        color: #ffdede;
        border-color: #723b3b;
        background: #2a0f16;
    }

/* Small screens: tighten spacing a bit */
@media (max-width: 420px) {
    .auth-card {
        padding: 14px;
    }

    .form-field input {
        padding: 9px 10px;
    }
}