:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --primary-light: #eeeffe;
    --text-main: #1f2937;
    --text-muted: #6b7280;
    --border: #d1d5db;
    --border-focus: #818cf8;
    --bg-page: #f9fafb;
    --bg-card: #ffffff;
    --radius: 12px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
}

body {
    min-height: 100vh;
    background-color: var(--bg-page);
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 440px;
    padding: 40px 32px;
    border-radius: var(--radius);
    background: var(--bg-card);
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.header-area {
    text-align: center;
    margin-bottom: 28px;
}

.login-logo {
    display: block;
    margin: 0 auto 16px auto;
    object-fit: contain;
}

h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: -0.02em;
    margin-bottom: 6px;
}

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

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

.input-group {
    position: relative;
    display: flex;
    flex-direction: column;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

input {
    width: 100%;
    padding: 12px 16px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    font-size: 15px;
    color: var(--text-main);
    background-color: var(--bg-card);
    transition: all 0.2s ease;
}

input::placeholder {
    color: #9ca3af;
}

input:focus {
    border-color: var(--border-focus);
    outline: none;
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.1);
}

input:read-only {
    background-color: #f3f4f6;
    color: var(--text-muted);
    cursor: not-allowed;
    border-color: var(--border);
}

button {
    width: 100%;
    padding: 13px;
    border-radius: var(--radius);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s ease;
    display: inline-flex;
    justify-content: center;
    align-items: center;
}

.btn-primary {
    background-color: var(--primary);
    color: #ffffff;
    border: none;
    box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
}

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

.btn-primary:active {
    transform: scale(0.98);
}

.btn-otp {
    background-color: var(--primary-light);
    color: var(--primary);
    border: 1px solid rgba(79, 70, 229, 0.2);
}

.btn-otp:hover {
    background-color: #e0e2fe;
}

.btn-otp:disabled {
    background-color: #f3f4f6;
    color: var(--text-muted);
    border-color: var(--border);
    cursor: not-allowed;
}

.collapsible-section {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.collapsible-section.show {
    max-height: 100px;
}

.footer {
    text-align: center;
    margin-top: 24px;
    font-size: 14px;
    color: var(--text-muted);
}

.footer a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    margin-left: 4px;
}

.footer a:hover {
    text-decoration: underline;
}