:root {
    --primary: #5856d6;
    --primary-dark: #4543b8;
    --primary-light: #eeedff;

    --page-bg: #f5f6fb;
    --surface: #ffffff;

    --text-main: #202235;
    --text-muted: #74778a;
    --border: #dfe1eb;

    --success: #168653;
    --success-bg: #eaf8f0;

    --danger: #d9364f;
    --danger-bg: #fff0f2;

    --radius: 12px;
    --shadow: 0 18px 55px rgba(31, 35, 75, 0.09);
}

/* =========================================================
   RESET & BASE
   ========================================================= */

* {
    box-sizing: border-box;
}

html {
    min-height: 100%;
    scroll-behavior: smooth;
}

body {
    margin: 0;
    min-height: 100vh;
    background: var(--page-bg);
    color: var(--text-main);
    font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI",
        Roboto, Arial, sans-serif;
    font-size: 14px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

button,
input {
    font: inherit;
}

button,
a,
input {
    -webkit-tap-highlight-color: transparent;
}

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

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

/* =========================================================
   PAGE LAYOUT
   ========================================================= */

.auth-page {
    display: grid;
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
    min-height: 100vh;
}

/* =========================================================
   LEFT BRAND PANEL
   ========================================================= */

.auth-brand {
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 100%;
    padding: 44px clamp(32px, 5vw, 76px);
    overflow: hidden;
    color: #ffffff;
    background:
        radial-gradient(
            circle at 90% 10%,
            rgba(255, 255, 255, 0.14),
            transparent 34%
        ),
        linear-gradient(145deg, #6865e8 0%, #514ec4 52%, #37358e 100%);
}

.auth-brand::before,
.auth-brand::after {
    position: absolute;
    content: "";
    pointer-events: none;
    border: 1px solid rgba(255, 255, 255, 0.12);
    border-radius: 50%;
}

.auth-brand::before {
    width: 360px;
    height: 360px;
    right: -180px;
    bottom: -90px;
}

.auth-brand::after {
    width: 240px;
    height: 240px;
    right: -120px;
    bottom: -30px;
}

.brand-logo {
    position: relative;
    z-index: 1;
    display: inline-flex;
    align-items: center;
    gap: 12px;
    width: fit-content;
    color: #ffffff;
}

.brand-logo:hover {
    color: #ffffff;
}

.brand-mark {
    display: grid;
    width: 46px;
    height: 46px;
    place-items: center;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 13px;
    background: rgba(255, 255, 255, 0.15);
    font-size: 23px;
    font-weight: 800;
    letter-spacing: -1.5px;
}

.brand-name {
    font-size: 18px;
    font-weight: 750;
    letter-spacing: -0.4px;
}

.brand-content {
    position: relative;
    z-index: 1;
    max-width: 490px;
    margin: 70px 0;
}

.brand-eyebrow,
.form-eyebrow {
    display: inline-block;
    font-size: 11px;
    font-weight: 750;
    letter-spacing: 2px;
}

.brand-eyebrow {
    color: #dedcff;
}

.brand-content h1 {
    max-width: 430px;
    margin: 20px 0;
    font-size: clamp(34px, 4vw, 52px);
    font-weight: 760;
    line-height: 1.15;
    letter-spacing: -1.8px;
}

.brand-content > p {
    max-width: 410px;
    margin: 0;
    color: rgba(255, 255, 255, 0.82);
    font-size: 15px;
    line-height: 1.9;
}

.brand-features {
    display: grid;
    gap: 17px;
    margin-top: 36px;
}

.brand-feature {
    display: flex;
    align-items: center;
    gap: 12px;
    color: rgba(255, 255, 255, 0.95);
    font-size: 13px;
}

.feature-icon {
    display: grid;
    flex: 0 0 25px;
    width: 25px;
    height: 25px;
    place-items: center;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.12);
    font-size: 12px;
    font-weight: 800;
}

.brand-footer {
    position: relative;
    z-index: 1;
    margin: 0;
    color: rgba(255, 255, 255, 0.65);
    font-size: 11px;
}

/* =========================================================
   RIGHT FORM PANEL
   ========================================================= */

.auth-form-section {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 0;
    padding: 48px clamp(24px, 5vw, 76px);
    background: var(--surface);
}

.auth-form-container {
    width: 100%;
    max-width: 440px;
    margin: auto;
}

.form-heading {
    margin-bottom: 26px;
}

.form-eyebrow {
    color: var(--primary);
}

.form-heading h2 {
    margin: 9px 0 5px;
    color: var(--text-main);
    font-size: clamp(25px, 2.5vw, 31px);
    font-weight: 760;
    line-height: 1.3;
    letter-spacing: -0.8px;
}

.form-heading p {
    margin: 0;
    color: var(--text-muted);
    font-size: 13px;
}

/* =========================================================
   SERVER-SIDE ERROR ALERT
   ========================================================= */

.alert {
    margin: 0 0 22px;
    padding: 14px 16px;
    border: 1px solid transparent;
    border-radius: 10px;
    font-size: 12px;
}

.alert-error {
    border-color: #ffd4db;
    background: var(--danger-bg);
    color: #a92038;
}

.alert strong {
    display: block;
    margin-bottom: 5px;
}

.alert ul {
    display: grid;
    gap: 4px;
    margin: 0;
    padding-left: 18px;
}

/* =========================================================
   FORM FIELDS
   ========================================================= */

#signupForm {
    display: grid;
    gap: 17px;
}

.form-group {
    display: flex;
    flex-direction: column;
    min-width: 0;
    gap: 7px;
}

.form-group label {
    color: #36384b;
    font-size: 12px;
    font-weight: 700;
}

.form-group label span {
    color: var(--danger);
}

.form-group input {
    display: block;
    width: 100%;
    min-width: 0;
    height: 47px;
    padding: 0 14px;
    outline: none;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: #ffffff;
    color: var(--text-main);
    font-size: 13px;
    transition:
        border-color 0.2s ease,
        box-shadow 0.2s ease,
        background-color 0.2s ease;
}

.form-group input::placeholder {
    color: #a0a3b3;
    opacity: 1;
}

.form-group input:hover {
    border-color: #b8bad0;
}

.form-group input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(88, 86, 214, 0.12);
}

.form-group input.is-valid {
    border-color: var(--success);
    background-color: #fcfffd;
}

.form-group input.is-valid:focus {
    box-shadow: 0 0 0 3px rgba(22, 134, 83, 0.1);
}

.form-group input.is-invalid {
    border-color: var(--danger);
    background-color: #fffdfd;
}

.form-group input.is-invalid:focus {
    box-shadow: 0 0 0 3px rgba(217, 54, 79, 0.1);
}

.input-hint,
.field-feedback,
.password-hint {
    display: block;
    min-height: 0;
    margin: 0;
    color: var(--text-muted);
    font-size: 11px;
    line-height: 1.5;
    overflow-wrap: anywhere;
}

.field-feedback:empty {
    display: none;
}

.field-feedback.is-success,
.password-hint.is-success {
    color: var(--success);
}

.field-feedback.is-error,
.password-hint.is-error {
    color: var(--danger);
}

/* =========================================================
   PASSWORD INPUT & VISIBILITY BUTTON
   ========================================================= */

.password-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.password-wrapper input {
    padding-right: 67px;
}

.password-toggle {
    position: absolute;
    top: 50%;
    right: 10px;
    padding: 5px 6px;
    transform: translateY(-50%);
    border: 0;
    border-radius: 6px;
    background: transparent;
    color: var(--primary);
    font-size: 11px;
    font-weight: 750;
    cursor: pointer;
}

.password-toggle:hover {
    background: var(--primary-light);
}

.password-toggle:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* =========================================================
   CREATE ACCOUNT BUTTON
   ========================================================= */

.btn-primary {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-height: 48px;
    margin-top: 5px;
    padding: 12px 18px;
    border: 0;
    border-radius: var(--radius);
    background: var(--primary);
    color: #ffffff;
    font-size: 13px;
    font-weight: 750;
    cursor: pointer;
    transition:
        background-color 0.2s ease,
        box-shadow 0.2s ease,
        transform 0.2s ease;
}

.btn-primary:hover:not(:disabled) {
    transform: translateY(-1px);
    background: var(--primary-dark);
    box-shadow: 0 7px 18px rgba(88, 86, 214, 0.2);
}

.btn-primary:focus-visible {
    outline: 3px solid rgba(88, 86, 214, 0.3);
    outline-offset: 3px;
}

.btn-primary:disabled {
    background: #a6a5d8;
    cursor: wait;
    box-shadow: none;
    transform: none;
}

/* =========================================================
   SIGN-IN LINK
   ========================================================= */

.login-prompt {
    margin: 4px 0 0;
    color: var(--text-muted);
    font-size: 12px;
    text-align: center;
}

.login-prompt a {
    margin-left: 3px;
    font-weight: 750;
}

.login-prompt a:hover {
    text-decoration: underline;
}

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

@media (max-width: 900px) {
    .auth-page {
        grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    }

    .auth-brand {
        padding: 34px 28px;
    }

    .auth-form-section {
        padding: 40px 28px;
    }

    .brand-content h1 {
        font-size: 37px;
    }
}

@media (max-width: 680px) {
    .auth-page {
        display: flex;
        flex-direction: column;
        min-height: 100vh;
    }

    .auth-brand {
        min-height: auto;
        padding: 24px 24px 28px;
    }

    .brand-mark {
        width: 40px;
        height: 40px;
        font-size: 21px;
    }

    .brand-name {
        font-size: 16px;
    }

    .brand-content {
        margin: 35px 0 12px;
    }

    .brand-content h1 {
        max-width: 400px;
        margin: 12px 0;
        font-size: 31px;
        letter-spacing: -1px;
    }

    .brand-content > p {
        font-size: 13px;
        line-height: 1.7;
    }

    .brand-features {
        gap: 10px;
        margin-top: 20px;
    }

    .brand-feature {
        font-size: 12px;
    }

    .brand-footer {
        margin-top: 24px;
    }

    .auth-form-section {
        flex: 1;
        padding: 35px 24px 42px;
    }

    .auth-form-container {
        max-width: 460px;
    }

    .form-heading h2 {
        font-size: 27px;
    }
}

@media (max-width: 380px) {
    .auth-brand {
        padding: 20px 18px 24px;
    }

    .auth-form-section {
        padding: 28px 18px 34px;
    }

    #signupForm {
        gap: 15px;
    }

    .form-group input {
        height: 45px;
        font-size: 12px;
    }

    .brand-content h1 {
        font-size: 28px;
    }
}

/* =========================================================
   REDUCED MOTION ACCESSIBILITY
   ========================================================= */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
    }
}