* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    user-select: none;
    text-decoration: none;
}

body {
    width: 100%;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    font-size: 12px;
    color: var(--color-text);
    font-family: var(--font-sans);
    background-color: var(--color-cream);
    transition: background-color 1.2s ease, color 1.2s ease;
}



.shell {
    position: relative;
    width: 90%;
    max-width: 1200px;
    height: 600px;
    padding: 25px;
    background-color: var(--color-card);
    box-shadow: 0 4px 12px rgba(232, 160, 191, 0.15);
    border-radius: 12px;
    overflow: hidden;
    border: 2px solid var(--color-border);
    display: flex;
    align-items: center;
}

.container {
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    width: 60%;
    height: 100%;
    padding: 25px;
    background-color: var(--color-card);
    transition: 1.25s;
}

.form {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    width: 100%;
    height: 100%;
}

.form_input {
    width: 350px;
    height: 40px;
    margin: 4px 0;
    padding-left: 25px;
    font-size: 13px;
    letter-spacing: .15px;
    border: 1px solid var(--color-border);
    outline: none;
    background-color: var(--color-card);
    transition: .25s ease;
    border-radius: 8px;
    box-shadow: inset 2px 2px 4px rgba(232, 213, 196, 0.3), inset -2px -2px 4px rgba(255, 253, 247, 0.8);
    color: var(--color-text);
    font-family: var(--font-sans);
}

.form_input:focus {
    border-color: var(--color-primary);
    box-shadow: inset 4px 4px 4px rgba(232, 213, 196, 0.4), inset -4px -4px 4px rgba(255, 253, 247, 0.9);
}

.form_span {
    margin-top: 30px;
    margin-bottom: 12px;
    color: var(--color-text-muted);
}

.form_link {
    color: var(--color-text);
    font-size: 15px;
    margin-top: 25px;
    border-bottom: 1px solid var(--color-border);
    line-height: 2;
    transition: color 0.3s ease;
}

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

.title {
    font-size: 34px;
    font-weight: 700;
    line-height: 3;
    color: var(--color-text);
    letter-spacing: 10px;
    font-family: var(--font-sans);
}

.description {
    font-size: 14px;
    letter-spacing: .25px;
    text-align: center;
    line-height: 1.6;
    color: var(--color-text-muted);
}

.button {
    width: 180px;
    height: 50px;
    border-radius: 25px;
    margin-top: 50px;
    font-weight: 700;
    font-size: 14px;
    letter-spacing: 1.15px;
    background-color: var(--color-primary);
    color: #f9f9f9;
    box-shadow: 8px 8px 16px rgba(232, 213, 196, 0.3), -8px -8px 16px rgba(255, 253, 247, 0.8);
    border: none;
    outline: none;
    transition: all 0.3s ease;
    font-family: var(--font-sans);
}

.button:hover {
    background-color: var(--color-primary);
    box-shadow: 6px 6px 12px rgba(232, 213, 196, 0.4), -6px -6px 12px rgba(255, 253, 247, 0.9);
}

.button:active {
    background-color: var(--color-primary);
    box-shadow: 2px 2px 4px rgba(232, 213, 196, 0.5), -2px -2px 4px rgba(255, 253, 247, 1);
    transform: scale(0.97);
}

.a-container {
    z-index: 100;
    left: calc(100% - 60%);
}

.b-container {
    z-index: 0;
    left: calc(100% - 60%);
}

.switch {
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 40%;
    padding: 50px;
    z-index: 200;
    transition: 1.25s;
    background-color: var(--color-card);
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(232, 160, 191, 0.15);
    border: none;
}

.switch_container {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    position: absolute;
    width: 400px;
    padding: 50px 55px;
    transition: 1.25s;
}

.switch_button {
    cursor: pointer;
}

.switch_button:hover,
.submit:hover {
    box-shadow: 6px 6px 10px #d1d9e6, -6px -6px 10px #f9f9f9;
}

.switch_button:active,
.switch_button:focus,
.submit:active,
.submit:focus {
    box-shadow: 2px 2px 6px #d1d9e6, -2px -2px 6px #f9f9f9;
    transform: scale(0.97);
    transition: .25s;
}

.switch_button,
.submit {
    cursor: pointer;
}

.is-txr {
    left: calc(100% - 40%);
    transition: 1.25s;
    transform-origin: left;
}

.is-txl {
    left: 0;
    transition: 1.25s;
    transform-origin: right;
}

.is-z {
    z-index: 200;
    transition: 1.25s;
}

.is-hidden {
    visibility: hidden;
    opacity: 0;
    position: absolute;
    transition: 1.25s;
}

.is-gx {
    animation: is-gx 1.25s;
}

/* 夜间模式：登录页面样式 */
html.night-mode body .shell {
    box-shadow: 0 4px 12px rgba(155, 123, 184, 0.15);
}

html.night-mode body .form_input {
    box-shadow: inset 2px 2px 4px rgba(40, 40, 70, 0.3), inset -2px -2px 4px rgba(60, 60, 100, 0.8);
    border-color: var(--color-border);
}

html.night-mode body .form_input:focus {
    box-shadow: inset 4px 4px 4px rgba(40, 40, 70, 0.4), inset -4px -4px 4px rgba(60, 60, 100, 0.9);
    border-color: var(--color-primary);
}

html.night-mode body .button {
    box-shadow: 8px 8px 16px rgba(40, 40, 70, 0.3), -8px -8px 16px rgba(60, 60, 100, 0.8);
}

html.night-mode body .button:hover {
    box-shadow: 6px 6px 12px rgba(40, 40, 70, 0.4), -6px -6px 12px rgba(60, 60, 100, 0.9);
}

html.night-mode body .button:active {
    box-shadow: 2px 2px 4px rgba(40, 40, 70, 0.5), -2px -2px 4px rgba(60, 60, 100, 1);
}

html.night-mode body .switch {
    box-shadow: 0 4px 12px rgba(155, 123, 184, 0.15);
}

html.night-mode body .switch_button:hover,
html.night-mode body .submit:hover {
    box-shadow: 6px 6px 10px rgba(40, 40, 70, 0.4), -6px -6px 10px rgba(60, 60, 100, 0.9);
}

html.night-mode body .switch_button:active,
html.night-mode body .switch_button:focus,
html.night-mode body .submit:active,
html.night-mode body .submit:focus {
    box-shadow: 2px 2px 6px rgba(40, 40, 70, 0.5), -2px -2px 6px rgba(60, 60, 100, 1);
}

.error-message {
    color: red;
    font-size: 12px;
    margin-top: 5px;
    display: block;
    width: 350px;
    text-align: left;
    padding-left: 25px;
}