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

:root {
    --black: #030810;
    --navy: #0a1628;
    --blue: #00a8ff;
    --cyan: #00d4ff;
    --text: #e8edf4;
    --text-dim: #7a8ba5;
    --text-muted: #4a5a6f;
    --blue-glow: rgba(0, 168, 255, 0.15);
    --blue-glow-strong: rgba(0, 168, 255, 0.35);
    --border: rgba(0, 168, 255, 0.12);
    --font: -apple-system, 'Segoe UI', 'Helvetica Neue', Helvetica, sans-serif;
    --font-mono: 'SF Mono', 'Cascadia Code', 'Fira Code', 'JetBrains Mono', 'Consolas', monospace;
}

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: var(--font);
    background: var(--black);
    color: var(--text);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
}

/* ── Particle Canvas ── */

#particles {
    position: fixed;
    inset: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

/* ── Content ── */

.content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 2rem;
    max-width: 540px;
    width: 100%;
}

/* ── Logo ── */

.logo-wrap {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.logo {
    width: 72px;
    height: 48px;
    animation: pulse-glow 3s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% {
        filter: drop-shadow(0 0 8px rgba(0, 168, 255, 0.4))
                drop-shadow(0 0 16px rgba(0, 168, 255, 0.1));
    }
    50% {
        filter: drop-shadow(0 0 16px rgba(0, 168, 255, 0.7))
                drop-shadow(0 0 32px rgba(0, 168, 255, 0.25));
    }
}

/* ── Brand Name ── */

.brand-name {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    letter-spacing: 0.18em;
    line-height: 1;
    margin-bottom: 0.75rem;
    background: linear-gradient(
        90deg,
        var(--text) 0%,
        var(--blue) 25%,
        var(--cyan) 50%,
        var(--blue) 75%,
        var(--text) 100%
    );
    background-size: 200% auto;
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: shimmer 4s linear infinite;
}

@keyframes shimmer {
    0%   { background-position: 0% center; }
    100% { background-position: 200% center; }
}

/* ── Tagline ── */

.tagline {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: var(--text-dim);
    font-weight: 400;
    letter-spacing: 0.04em;
    margin-bottom: 2rem;
}

/* ── Divider ── */

.divider {
    width: 60px;
    height: 1px;
    background: var(--border);
    margin: 0 auto 2rem;
}

/* ── Teaser ── */

.teaser {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.25em;
    color: var(--blue);
    text-transform: uppercase;
    margin-bottom: 2.5rem;
}

/* ── Signup Form ── */

.signup-form {
    width: 100%;
}

.form-row {
    display: flex;
    gap: 0;
    max-width: 440px;
    margin: 0 auto;
    border: 1px solid var(--border);
    border-radius: 6px;
    overflow: hidden;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    background: rgba(10, 22, 40, 0.65);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.form-row:focus-within {
    border-color: var(--blue-glow-strong);
    box-shadow: 0 0 20px rgba(0, 168, 255, 0.1);
}

#email-input {
    flex: 1;
    min-width: 0;
    background: transparent;
    border: none;
    padding: 0.875rem 1.25rem;
    color: var(--text);
    font-family: var(--font);
    font-size: 0.9rem;
    outline: none;
}

#email-input::placeholder {
    color: var(--text-muted);
}

#submit-btn {
    background: var(--blue);
    color: var(--black);
    border: none;
    padding: 0.875rem 1.5rem;
    font-family: var(--font);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    cursor: pointer;
    transition: background 0.3s ease;
    white-space: nowrap;
    position: relative;
    flex-shrink: 0;
}

#submit-btn:hover {
    background: var(--cyan);
}

#submit-btn:disabled {
    cursor: not-allowed;
    opacity: 0.7;
}

#submit-btn.loading .btn-text {
    visibility: hidden;
}

#submit-btn.loading .btn-spinner {
    display: block;
}

.btn-spinner {
    display: none;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 18px;
    height: 18px;
    border: 2px solid rgba(3, 8, 16, 0.3);
    border-top-color: var(--black);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: translate(-50%, -50%) rotate(360deg); }
}

/* ── Form Messages ── */

.form-message {
    margin-top: 1rem;
    font-size: 0.85rem;
    min-height: 1.5em;
    transition: opacity 0.3s ease;
}

.form-message.success {
    color: #00cc88;
}

.form-message.error {
    color: #ff4d6a;
}

/* ── Footer ── */

.footer {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    text-align: center;
    padding: 1.5rem;
    z-index: 1;
}

.footer p {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    letter-spacing: 0.12em;
    color: var(--text-muted);
    text-transform: uppercase;
}

/* ── Reduced Motion ── */

@media (prefers-reduced-motion: reduce) {
    .logo {
        animation: none;
        filter: drop-shadow(0 0 12px rgba(0, 168, 255, 0.5));
    }

    .brand-name {
        animation: none;
        background-position: 50% center;
    }

    .btn-spinner {
        animation: none;
    }
}

/* ── Mobile ── */

@media (max-width: 640px) {
    .content {
        padding: 1.5rem;
    }

    .form-row {
        flex-direction: column;
    }

    #email-input {
        border-bottom: 1px solid var(--border);
    }

    #submit-btn {
        padding: 0.875rem;
    }
}