* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --dark: #0f172a;
    --text: #334155;
    --muted: #64748b;
    --light: #f8fafc;
    --border: #e2e8f0;
    --white: #ffffff;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family:
        Inter,
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        sans-serif;

    color: var(--text);
    background: var(--white);
    line-height: 1.6;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    width: min(1180px, 92%);
    margin: auto;
}


/* =========================
   NAVBAR
========================= */

.navbar {
    height: 72px;
    border-bottom: 1px solid var(--border);
    background: rgba(255,255,255,.95);
}

.nav-container {
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 21px;
    font-weight: 800;
    color: var(--dark);
}

.logo-mark {
    width: 36px;
    height: 36px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 9px;

    background: var(--primary);
    color: white;

    font-weight: 800;
}

nav {
    display: flex;
    align-items: center;
    gap: 32px;

    font-size: 14px;
}

nav a {
    color: var(--muted);
}

nav a:hover {
    color: var(--primary);
}

.nav-login {
    padding: 9px 18px;

    border-radius: 7px;

    background: var(--dark);
    color: white !important;
}


/* =========================
   HERO
========================= */

.hero {
    padding: 100px 0;
    background:
        linear-gradient(
            135deg,
            #f8fafc 0%,
            #eff6ff 100%
        );
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 460px;
    gap: 80px;
    align-items: center;
}

.badge {
    display: inline-block;

    padding: 6px 12px;

    border-radius: 20px;

    background: #dbeafe;
    color: #1d4ed8;

    font-size: 12px;
    font-weight: 700;
}

.hero h1 {
    margin-top: 22px;

    font-size: clamp(42px, 5vw, 64px);
    line-height: 1.08;

    letter-spacing: -2px;

    color: var(--dark);
}

.hero h1 span {
    display: block;
    color: var(--primary);
}

.hero-content > p {
    margin-top: 25px;

    max-width: 620px;

    font-size: 18px;
    color: var(--muted);
}

.hero-buttons {
    margin-top: 35px;

    display: flex;
    gap: 14px;
}

.btn {
    display: inline-flex;

    align-items: center;
    justify-content: center;

    padding: 13px 24px;

    border-radius: 8px;

    font-size: 14px;
    font-weight: 700;

    transition: .2s;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background: white;
    color: var(--dark);
    border: 1px solid var(--border);
}

.btn-light {
    background: white;
    color: var(--primary);
}


/* =========================
   CHAT CARD
========================= */

.hero-card {
    background: white;

    border: 1px solid var(--border);

    border-radius: 18px;

    box-shadow:
        0 25px 60px rgba(15, 23, 42, .12);

    overflow: hidden;
}

.card-header {
    padding: 18px 20px;

    display: flex;
    justify-content: space-between;
    align-items: center;

    border-bottom: 1px solid var(--border);
}

.card-header strong {
    display: block;
    color: var(--dark);
}

.card-header small {
    color: var(--muted);
}

.status-dot {
    width: 10px;
    height: 10px;

    border-radius: 50%;

    background: #22c55e;
}

.chat {
    padding: 22px;
}

.message {
    max-width: 85%;

    padding: 12px 15px;

    margin-bottom: 15px;

    border-radius: 12px;

    font-size: 13px;
}

.user-message {
    margin-left: auto;

    background: #eff6ff;
    color: #1e40af;
}

.ai-message {
    background: #f8fafc;
    color: var(--text);
}


/* =========================
   FEATURES
========================= */

.features {
    padding: 100px 0;
}

.section-header {
    max-width: 700px;
    margin: auto;

    text-align: center;
}

.section-label {
    color: var(--primary);

    font-size: 12px;
    font-weight: 800;

    letter-spacing: 1.5px;
}

.section-header h2,
.about h2 {
    margin-top: 12px;

    color: var(--dark);

    font-size: 38px;
    line-height: 1.2;
}

.section-header p {
    margin-top: 18px;
    color: var(--muted);
}

.feature-grid {
    margin-top: 55px;

    display: grid;
    grid-template-columns: repeat(4, 1fr);

    gap: 20px;
}

.feature-card {
    padding: 28px;

    border: 1px solid var(--border);
    border-radius: 14px;

    background: white;
}

.feature-icon {
    width: 44px;
    height: 44px;

    display: flex;
    align-items: center;
    justify-content: center;

    border-radius: 10px;

    background: #eff6ff;
    color: var(--primary);

    font-weight: 800;
}

.feature-card h3 {
    margin-top: 20px;
    color: var(--dark);
}

.feature-card p {
    margin-top: 10px;
    color: var(--muted);
    font-size: 14px;
}


/* =========================
   ABOUT
========================= */

.about {
    padding: 100px 0;

    background: var(--light);
}

.about-container {
    display: grid;

    grid-template-columns: 1fr 1fr;

    gap: 100px;
}

.about p {
    margin-bottom: 20px;
    color: var(--muted);
}


/* =========================
   CTA
========================= */

.cta {
    padding: 80px 0;

    text-align: center;

    background: var(--primary);
    color: white;
}

.cta h2 {
    font-size: 36px;
}

.cta p {
    margin: 10px 0 25px;

    opacity: .85;
}


/* =========================
   FOOTER
========================= */

footer {
    padding: 25px 0;

    border-top: 1px solid var(--border);

    font-size: 13px;
}

.footer-container {
    display: flex;
    justify-content: space-between;
    color: var(--muted);
}

.footer-container strong {
    color: var(--dark);
}

.footer-container span {
    margin-left: 10px;
}


/* =========================
   LOGIN
========================= */

.login-page {
    min-height: 100vh;

    background:
        linear-gradient(
            135deg,
            #f8fafc,
            #eff6ff
        );

    display: flex;
    align-items: center;
    justify-content: center;
}

.login-container {
    width: 420px;
    padding: 30px 20px;
}

.login-brand {
    text-align: center;
    margin-bottom: 25px;
}

.login-brand .logo {
    justify-content: center;
}

.login-brand p {
    margin-top: 8px;

    color: var(--muted);
    font-size: 14px;
}

.login-card {
    padding: 35px;

    background: white;

    border: 1px solid var(--border);

    border-radius: 15px;

    box-shadow:
        0 20px 50px rgba(15, 23, 42, .08);
}

.login-header h1 {
    color: var(--dark);
    font-size: 27px;
}

.login-header p {
    margin-top: 5px;
    color: var(--muted);
    font-size: 14px;
}

.login-error {
    margin-top: 20px;

    padding: 11px 13px;

    border-radius: 7px;

    background: #fef2f2;
    color: #b91c1c;

    font-size: 13px;
}

.form-group {
    margin-top: 22px;
}

.form-group label,
.password-label label {
    display: block;

    margin-bottom: 7px;

    color: var(--dark);

    font-size: 13px;
    font-weight: 600;
}

.form-group input {
    width: 100%;

    padding: 12px 13px;

    border: 1px solid var(--border);

    border-radius: 7px;

    font-size: 14px;

    outline: none;
}

.form-group input:focus {
    border-color: var(--primary);

    box-shadow:
        0 0 0 3px rgba(37,99,235,.1);
}

.password-label {
    display: flex;
    justify-content: space-between;
}

.password-label a {
    color: var(--primary);
    font-size: 12px;
}

.remember {
    margin: 18px 0;

    color: var(--muted);
    font-size: 13px;
}

.remember input {
    margin-right: 6px;
}

.btn-full {
    width: 100%;
    border: none;
    cursor: pointer;
}

.login-footer {
    margin-top: 25px;

    text-align: center;

    font-size: 13px;
}

.login-footer a {
    color: var(--primary);
}

.login-copyright {
    margin-top: 20px;

    text-align: center;

    color: var(--muted);

    font-size: 12px;
}


/* =========================
   RESPONSIVE
========================= */

@media (max-width: 900px) {

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

    .feature-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-container {
        grid-template-columns: 1fr;
        gap: 30px;
    }

}

@media (max-width: 600px) {

    nav a:not(.nav-login) {
        display: none;
    }

    .hero {
        padding: 70px 0;
    }

    .hero h1 {
        font-size: 42px;
    }

    .hero-buttons {
        flex-direction: column;
    }

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

    .section-header h2,
    .about h2 {
        font-size: 30px;
    }

    .login-container {
        width: 100%;
    }

}