/* GIAO DIỆN SOFT BRUTALISM & NAMESPACED - LOG & EXPONENT CALCULATOR */
.logexp-container {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    max-width: 900px; margin: 20px auto;
    border: 3px solid #111111; border-radius: 12px;
    box-shadow: 6px 6px 0px #111111; padding: 30px;
    background: #ffffff; color: #111111; box-sizing: border-box;
}

.logexp-container * { box-sizing: border-box; }

.logexp-title {
    font-family: 'Montserrat', sans-serif; font-size: 2rem; text-align: center;
    text-transform: uppercase; margin-top: 0; margin-bottom: 10px; font-weight: 900;
}

.logexp-desc { text-align: center; color: #444; font-weight: 600; margin-bottom: 30px; line-height: 1.5; }

.logexp-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; margin-bottom: 30px; }

/* Thẻ Card chính */
.logexp-card {
    border: 3px solid #111111; border-radius: 10px; padding: 25px;
    box-shadow: 4px 4px 0px #111111; display: flex; flex-direction: column;
}
.bg-yellow { background-color: #fdfd96; }
.bg-green { background-color: #e2f0cb; }

.logexp-card-header {
    font-family: 'Montserrat', sans-serif; font-size: 1.2rem; font-weight: 900;
    margin: 0 0 20px 0; border-bottom: 3px dashed #111; padding-bottom: 10px; text-transform: uppercase;
}

.logexp-input-group { margin-bottom: 15px; }
.logexp-label { display: block; font-weight: 800; font-size: 1rem; margin-bottom: 8px; color: #111; }

.logexp-input {
    width: 100%; padding: 12px 15px; font-size: 1.2rem; font-weight: 800;
    font-family: 'Courier New', Courier, monospace; border: 3px solid #111111;
    border-radius: 6px; outline: none; background-color: #fff; box-shadow: inset 2px 2px 0px rgba(0,0,0,0.05);
}
.logexp-input:focus { border-color: #2d7bb5; }

/* Dropdown chọn hệ Logarit */
.logexp-base-selector { display: flex; gap: 10px; }
.logexp-select {
    width: 140px; padding: 10px; font-size: 0.9rem; font-weight: 700; font-family: 'Inter', sans-serif;
    border: 3px solid #111; border-radius: 6px; outline: none; background-color: #fff; cursor: pointer;
}

.logexp-btn {
    width: 100%; background-color: #111; color: #fff; font-family: 'Montserrat', sans-serif;
    font-weight: 900; font-size: 1.1rem; padding: 15px; border: 3px solid #111; border-radius: 6px;
    cursor: pointer; box-shadow: 4px 4px 0px #666; transition: transform 0.1s; margin-top: 10px;
}
.logexp-btn:active { transform: translate(4px, 4px); box-shadow: 0px 0px 0px #666; }

/* Khối Kết Quả */
.logexp-result-box {
    margin-top: 20px; background-color: #fff; border: 3px solid #111; border-radius: 8px;
    padding: 15px; box-shadow: 3px 3px 0px #111; position: relative; text-align: center;
}
.logexp-equation { font-size: 1rem; font-weight: 700; color: #555; margin-bottom: 5px; }
.logexp-value { font-family: 'Montserrat', monospace; font-size: 1.8rem; font-weight: 900; color: #e05a47; word-break: break-all; margin-bottom: 15px;}
.logexp-error { margin-top: 15px; color: #e05a47; font-weight: 800; font-size: 0.95rem; text-align: center; display: none; }

.logexp-btn-copy {
    background-color: #e6f7ff; border: 2px solid #111; border-radius: 6px;
    padding: 8px 15px; font-weight: 800; font-size: 0.9rem; cursor: pointer; box-shadow: 2px 2px 0px #111;
}
.logexp-btn-copy:active { transform: translate(2px, 2px); box-shadow: 0px 0px 0px #111; }

/* Góc ghi nhớ */
.logexp-formulas {
    background-color: #f4f4f4; border: 3px dashed #111; border-radius: 10px; padding: 20px;
}
.logexp-formulas-title { margin: 0 0 10px 0; font-family: 'Montserrat', sans-serif; font-size: 1.1rem; }
.logexp-list { margin: 0; padding-left: 20px; color: #333; line-height: 1.6; }

/* Toast */
#logexpToast {
    visibility: hidden; min-width: 200px; background-color: #111111; color: #ffffff;
    text-align: center; border-radius: 8px; padding: 12px; position: fixed;
    z-index: 9999; bottom: 30px; left: 50%; transform: translateX(-50%);
    font-weight: bold; opacity: 0; transition: opacity 0.3s, bottom 0.3s;
}
#logexpToast.show { visibility: visible; opacity: 1; bottom: 50px; }

@media (max-width: 800px) {
    .logexp-grid { grid-template-columns: 1fr; }
    .logexp-base-selector { flex-direction: column; }
    .logexp-select { width: 100%; }
}