/* ==============================
   1. RESET AND BASE
============================== */

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

:root {
    --primary: #23364D;
    --primary-hover: #192A3D;
    --background: #F7F6F2;
    --surface: #FFFFFF;
    --text: #263238;
    --text-muted: #84909B;
    --border: #E5E7EB;
    --danger: #DC2626;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: Arial, Helvetica, sans-serif;
    background-color: var(--background);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.5;
}

button,
input,
textarea,
select {
    font: inherit;
}

button {
    -webkit-tap-highlight-color: transparent;
    cursor: pointer;
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

/* ==============================
   2. APP CONTAINER
============================== */

#app {
    width: 100%;
    min-height: 100vh;
    padding: 24px;
}

/* Chỉ căn giữa khi đang hiển thị màn hình đăng nhập. */
#app:has(.login-container) {
    display: flex;
    justify-content: center;
    align-items: center;
}

/* ==============================
   3. LOGIN SCREEN
============================== */

.login-container {
    width: 100%;
    max-width: 420px;
    background-color: var(--surface);
    padding: 40px 32px;
    border: 1px solid var(--border);
    border-radius: 20px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.05);
}

/* Logo */

.login-logo {
    text-align: center;
    margin-bottom: 32px;
}

.login-logo .logo-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    background-color: var(--primary);
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 18px;
    font-size: 28px;
}

.login-logo h1 {
    font-size: 24px;
    color: var(--primary);
    margin-bottom: 8px;
}

.login-logo p {
    font-size: 14px;
    color: var(--text-muted);
}

/* ==============================
   4. FORM
============================== */

.login-form {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 14px;
    font-weight: 600;
}

.form-group input {
    width: 100%;
    height: 48px;
    padding: 0 14px;
    border: 1px solid var(--border);
    border-radius: 10px;
    background-color: var(--surface);
    color: var(--text);
    font-size: 16px;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(35, 54, 77, 0.08);
}

.form-group input:disabled {
    background-color: var(--background);
    cursor: not-allowed;
}

/* ==============================
   5. LOGIN BUTTON
============================== */

.login-button {
    width: 100%;
    min-height: 50px;
    margin-top: 8px;
    border: none;
    border-radius: 10px;
    background-color: var(--primary);
    color: white;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.2s, opacity 0.2s;
}

.login-button:hover {
    background-color: var(--primary-hover);
}

.login-button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

/* ==============================
   6. ERROR MESSAGE
============================== */

.login-error {
    color: var(--danger);
    font-size: 13px;
    text-align: center;
    display: none;
}

/* ==============================
   7. MOBILE RESPONSIVE
============================== */

@media (max-width: 480px) {
    #app {
        padding: 16px;
    }

    .login-container {
        padding: 32px 22px;
        border-radius: 16px;
    }

    .login-logo h1 {
        font-size: 22px;
    }
}

/* ==============================
   8. REDUCED MOTION
============================== */

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