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

:root {
    --black: #000000;
    --white: #ffffff;
    --gray-light: #f8f8f8;
    --gray-medium: #e0e0e0;
    --gray-dark: #333333;
}

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

body {
    font-family: 'Space Grotesk', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--white);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: 480px;
    margin: 0 auto;
}

.content {
    text-align: center;
    animation: fadeIn 1s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.title {
    font-family: 'Space Grotesk', sans-serif;
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 700;
    color: var(--black);
    margin-bottom: 24px;
    line-height: 1.1;
    letter-spacing: -1px;
}

.subtitle {
    font-family: 'Inter', sans-serif;
    font-size: clamp(1rem, 3vw, 1.15rem);
    color: var(--gray-dark);
    margin-bottom: 16px;
    font-weight: 400;
    letter-spacing: -0.2px;
    line-height: 1.6;
}

/* Divider line */
.subtitle::after {
    content: '';
    display: block;
    width: 80px;
    height: 2px;
    background: var(--black);
    margin: 32px auto;
}

.email-form {
    margin-top: 32px;
}

.input-wrapper {
    position: relative;
    display: flex;
    gap: 8px;
    margin-bottom: 12px;
}

.email-input {
    flex: 1;
    padding: 18px 24px;
    font-size: 16px;
    font-family: 'Inter', sans-serif;
    border: 2px solid var(--black);
    border-radius: 12px;
    background: var(--white);
    color: var(--black);
    outline: none;
    transition: all 0.2s ease;
    box-shadow: 4px 4px 0px var(--black);
}

.email-input::placeholder {
    color: var(--gray-dark);
    opacity: 0.6;
}

.email-input:focus {
    border-color: var(--black);
    background: var(--gray-light);
    box-shadow: 6px 6px 0px var(--black);
    transform: translate(-2px, -2px);
}

.submit-btn {
    padding: 18px 32px;
    font-size: 16px;
    font-weight: 600;
    font-family: 'Space Grotesk', sans-serif;
    border: 2px solid var(--black);
    border-radius: 12px;
    background: var(--black);
    color: var(--white);
    cursor: pointer;
    transition: all 0.2s ease;
    outline: none;
    white-space: nowrap;
    box-shadow: 4px 4px 0px var(--black);
    position: relative;
    overflow: hidden;
}

.submit-btn:hover {
    background: var(--gray-dark);
    transform: translate(-2px, -2px);
    box-shadow: 6px 6px 0px var(--black);
}

.submit-btn:active {
    transform: translate(0, 0);
    box-shadow: 2px 2px 0px var(--black);
}

.submit-btn.loading {
    pointer-events: none;
}

.btn-loading {
    display: none;
}

.submit-btn.loading .btn-text {
    display: none;
}

.submit-btn.loading .btn-loading {
    display: inline;
    animation: checkmark 0.5s ease;
}

@keyframes checkmark {
    0% {
        transform: scale(0);
        opacity: 0;
    }
    50% {
        transform: scale(1.2);
    }
    100% {
        transform: scale(1);
        opacity: 1;
    }
}

.success-message,
.error-message {
    display: none;
    padding: 16px 24px;
    border-radius: 12px;
    font-size: 15px;
    font-family: 'Inter', sans-serif;
    font-weight: 500;
    margin-top: 16px;
    animation: slideIn 0.3s ease;
    border: 2px solid var(--black);
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.success-message {
    background: var(--white);
    color: var(--black);
    box-shadow: 3px 3px 0px var(--black);
}

.error-message {
    background: var(--black);
    color: var(--white);
    box-shadow: 3px 3px 0px var(--black);
}

.success-message.show,
.error-message.show {
    display: block;
}

/* Mobile optimizations */
@media (max-width: 480px) {
    body {
        padding: 16px;
    }

    .title {
        font-size: 1.75rem;
        margin-bottom: 12px;
    }

    .subtitle {
        font-size: 1rem;
        margin-bottom: 32px;
    }

    .input-wrapper {
        flex-direction: column;
        gap: 10px;
    }

    .email-input,
    .submit-btn {
        width: 100%;
        padding: 15px 20px;
    }

    .submit-btn {
        font-size: 15px;
    }
}

/* Very small screens */
@media (max-width: 360px) {
    .title {
        font-size: 1.5rem;
    }

    .email-input,
    .submit-btn {
        padding: 14px 18px;
        font-size: 15px;
    }
}